The following is a list of monsters and villains that have appeared in the Goosebumps franchise in alphabetical order.
- Abominable Snowman: A mysterious creature from the highest mountains in Alaska. The creature itself is harmless (save for a rabid appetite for trail mix), but the snow that comes from its habitat has the ability to freeze objects instantly. It appeared in the Goosebumps book, The Abominable Snowman of Pasadena.
- Ahmed: A quiet Egyptian dressed all in white with a red handkerchief and a ponytail, he is a descendant of the ancient Priestess Khala. His duty is to keep out all people from his tomb. He punishes all the invaders of his tomb by mummifying them alive. He appeared in the Goosebumps book, The Curse of the Mummy's Tomb.
- Aldebaranians: The aliens who resembled humans, with purple fur and meter-long arms. An Aldebaranian appeared and saved the reader from the blobs, and he declared that his race has nothing to do with the Vegans and the Arcturans, and he was exactly heading towards Earth, which delighted the reader. However, he then revealed that they will arrive on Earth ''in a while'', which is ''three thousands of your (reader's) years''. His kind appeared in the Give Yourself Goosebumps book, Zapped in Space.
- Alexander DuBrow : The antagonist of the book who betrayed Dr. D, Billy Deep, and Sheena Deep (the Deep family). He first appeared in the Goosebumps book, Deep Trouble.
- Alien Pig Mask: It is a furry, pig-face mask with curled yellow horns poking out of the top. It appeared in The Five Masks of Dr. Screem.
- Amaz-O: An evil magician who was turned into a rabbit. He appeared in the Goosebumps book, Bad Hare Day.
- Andrew Craw: A boy that gets his head pulled off and tries to find another head. He appears in the Goosebumps book, The Headless Ghost.
- Annabelle: A malevolent or benevolent entity who appears in a variety of forms, including as an evil witch, a good or evil ghost and even as the title of a steamboat. The one thing that they all share in common is that they all seem to have treasure in one form or another. She/it appeared in the Give Yourself Goosebumps book, Lost in Stinkeye Swamp.
- Annihilator 3000: A kid-sized toy robot with red lights for eyes. It has lasers in its hands and a freezer beam in its chest. It was supposed to come with plastic spacemen inside, but it was just a prototype. It starts using its lasers to destroy the reader's home. It appeared in the Give Yourself Goosebumps book Toy Terror: Batteries Included.
- Arcturians: A highly intelligent species of alien from the planet Arcturus. They resemble floating heads inside fish bowls which come in a variety of colors, and possess strong telepathic powers. The Arcturians believe they are the most intelligent forms of life and have begun to enslave other races by force. They appeared in the Give Yourself Goosebumps book, Zapped in Space.
- Aunt Dahlia: A witch who goes around claiming to be related to various families as a "great aunt", and then ages their children to senility with special prune cookies to marry them off to her friends, including Lillian and Mimi, for a price. When Tom threw a pitcher of prune juice at her, her face melted away to reveal a skull, then her whole body collapsed into dust. She appeared in the short story An Old Story.
- Axel: A flame-haired, skull-faced man who got his face removed. He works for Sybil Wicked. Despite being an antagonist for most of the book, it is possible to save him from a "De-Boner". He appears in Welcome to the Wicked Wax Museum.
- The Barking Ghosts: The ghosts of two friends who are in the form of spectral dogs. They had an evil spell cast upon them centuries ago after they fell down a large hole in an old shack. The spell doomed them to roam the woods of Maine as ghost dogs. They appeared in The Barking Ghost.
- Beasts: Huge blue koala-like creatures that play a deadly game of tag, in which the loser is eaten. It is also apparent that the better a Beast is at playing the game, the more abilities they are able to perform. Beasts are honor bound by the rules of the game. They appeared in The Beast from the East.
- The Bees: a swarm of bees from Why I'm Afraid of Bees.
- Big Al: Big Al is a round man with a big mustache and is the manager of the Carnival of Horrors. He has a yellow and black checkered shirt and has the power to enslave people in the book Escape from the Carnival of Horrors and the sequel, Return to the Carnival of Horrors.
- BIAJOLs: Brains in a Jar on Legs are thirsty for knowledge. They are the enemies in the game Brain Drain; the player has to suck the BIAJOLs' brain juice before they get to the player. The BIAJOLs are from the game Goosebumps HorrorLand.
- The Blob Monster: The Blob is a huge, pink blob creature with a mouth filled with razor sharp teeth and a long, sticky tongue. Originally an imaginary character created by Zackie Beauchamp, the Blob came to life through the power of a mysterious typewriter Zackie acquired from a burnt down antiques shop. The Blob went on a rampage through the city, as Zackie typed, and devoured his best friend Adam in the process. Zackie tried to destroy it using the typewriter but the Blob ate it before he had a chance. In the nick of time, Zackie deduced that he was the one who brought it to life, through whatever power the typewriter passed into him via an electric shock. Zackie willed the Blob away and returned Adam. However, it turned out the Blob was actually the one writing the story, and a friend, another blob, suggested rewriting the ending so the Blob wins. Appeared in The Blob That Ate Everyone. This monster may have been a tribute to the 1958 movie The Blob and the 1988 remake of the same name.
- Body Squeezers: Huge green aliens. The Body Squeezers used a meteorite to visit our Earth. They are able to absorb into humans by hugging them. Then they start taking over the human bodies. After the aliens get destroyed, a new, blue Body Squeezer species appears. Seen in two of the Goosebumps Series 2000 books, Invasion of the Body Squeezers Part 1 and 2. The blue species also appears in the Give Yourself Goosebumps Book Revenge of the Body Squeezers. These aliens are an obvious reference to Invasion of the Body Snatchers.
- Brandon Estep: The Most Powerful Ghost (MPG, for short) in The Curse of the Creeping Coffin. He wears a motorcycle outfit and has a "literal" iron fist.
- Brent Green: an invisible boy from My Best Friend is Invisible.
- Bugs: A terrifying race of small mites that render humans into parasitic hosts. They rule the world in an alternate universe accessible by the Transvator. Every couple of years the bugs devour most of their hosts inside a massive hive. Being infested by them is described as having thousands of tiny needles poked into the host at first until a massive euphoria sets in. Appeared in Elevator to Nowhere.
- Buzzard Hawks: They are huge creatures, how big you may ask? Bigger than a swan, they're black with outstretched wings and has a narrow head and sharp talons and strong enough to carry a golden retriever, but don't worry because they are blind, but you should worry a bit because they can smell fears. These hawks appear in the book Planet of the Lawn Gnomes.
- Captain Long Ben One-Leg: The Captain of a pirate ship that vanished behind a gray cloud. He appeared in the Goosebumps HorrorLand book, Creep from the Deep.
- Cats: A group of undead cats brought to life via a magical pet store called "Cat Heaven". In the event a cat suffers a violent death, their owner may bring them to the store and be brought to life before taking them back home. In the event the cat should leave the house, it will relive its violent death causing it to be picked up by the Cat Heaven workers and brought back to the store to be picked up. In the event that someone other then its owner should pick it up, it will turn violent and attack randomly. They appeared in Claws!
- Cave Spirit: A primordial spirit that represents the darkest of animal nature, he has the ability to control or possess animals and has the allegiance of many sorcerers and ghosts in Arizona. He resides within a bear skull, and when set free he will set out to imprison those who disturb his rest in the form of cave paintings. He has a variety of forms; the main one, being human form, is a powerful magician, and in animal form, he takes shape of a bear. He is the main villain in The Curse of the Cave Creatures.
- The Cemetery Man: A man in black who appears in Escape from Camp Run-For-Your-Life. He has power over the zombies that roam Zombie Mountain, and can also transform anyone into a zombie.
- Chin Chilla: This villainess appears only in the video game Attack of the Mutant. She is the second-in-command of the Masked Mutant and was imprisoned in a comic book by Magnificent Molecule Man. She has icy blue skin, has hoses for hands that shoot snowballs, and wears a bunch of chinchillas as a coat. The Masked Mutant tricks the player into giving him the comic book and releases Chin Chilla. The player deflects the snowballs she shoots at a scoreboard, causing it to fall and shatter the ice. After Chin Chilla is swept away by the current, the player only finds one of her boots.
- Chocolate Cake: A slab of chocolate cake made with a special "growth spice". It was made by Effy's Bakery in Midvale. It will make you a gorilla-sized giant and the cops will chase you, thinking you're a mutant alien. It appeared in the Give Yourself Goosebumps book, Beware of the Purple Peanut Butter.
- Chop Suey/Susan Chopman: The ghost of a cafeteria worker named Susan Chopman, who brandishes a meat cleaver and must be summoned by standing on your tip toes and saying "Chop Suey" three times in a row. She appeared in the short story, What's Cooking?
- Clarissa: A mysterious woman with the power to grant wishes, all of which come true in an unexpected way and with horrifying consequences. She appeared in the Goosebumps book, Be Careful What You Wish For...
- Compton Dawes: The realtor in Dark Falls. Compton sells dead house to the recently moved in families. Compton has stated that he is the only Compton in his family so that's how Amanda and Josh found out that the tombstone that said "Compton Dawes R.I.P. 1950-1980" was his and lied about being a living person in Dark Falls. Amanda thought she saw Compton at the end of the book even though they killed him but she was unsure this could have happened to the other folks of Dark Falls. He appears in the book Welcome to Dead House.
- Creeps: Reptilian beasts who are on a mission and believe Ricky is their Commander. They plan to put identity seeds in the school bake sale cookies to turn all the other students into Creeps. After realizing that he cannot stop them, he goes along with the plan after learning that once the other children become Creeps, Ricky will be their ruler and they will become his slaves. So he eats a cookie to become a Creep. If you can't beat them, join them. They appeared in the Goosebumps book, Calling All Creeps!
- Cronby: A cave troll who appears in Deep in the Jungle of Doom. His one intent is to eat or enslave those who happen upon him. He asks the reader trivia questions about the Goosebumps series.
- Cuckoo Clock: A cuckoo clock that sends a boy named Michael Webster back in time when he turns the bird's head backwards. He goes back in time every time he goes to sleep. Just before he disappears (his sister, Tara, already disappeared) he turns the head back. It appeared in the Goosebumps book, The Cuckoo Clock of Doom.
- Cuddle Bears: The owners of a bear-themed Amusement park named Cuddle Bear Land. But the employees does not wear costumes, they are real Cuddle Bears, who use Honey Crackers to transform children in stuffed souvenir bears. They appeared in the short story, Please Don't Feed The Bears!.
- Cuddles the Hamster: The hamster of the science teacher, Mr. Murphy. After eating some Monster Blood, Cuddles grows larger and larger, and meaner and meaner. But he reverts to his normal size, when the Monster Blood wears off. He appeared in the Goosebumps book, Monster Blood II.
- Curly the Skeleton: A skeleton who loves scary stories. Curly had no appearance in the Goosebumps books, but he became the mascot of the whole series. Curly has been illustrated on five Tales to Give You Goosebumps book covers. On most of them, Curly is seen with his pet bulldog.
- Dare: A "Gamesmaster" from KidsCare. Dare is a slim man with a cape and tattoos all over his body, and during his dangerous games his tattoos come to life, and can separate from him. If a tattoo is destroyed, it will be unable to return to Dare's body, and the part of his body that once held that tattoo will vanish completely. He appeared in the Give Yourself Goosebumps book, Attack of the Beastly Babysitter.
- Dark Falls Citizens: The Dark Falls Citizens died years ago because of an accident at the plastics factory which released a yellow gas over the town making them become zombie-like figures. To live the people of the town need fresh blood and make fake wills to think a family inherited a house from a dead relative. The town people normally wear hats because they will burn in the sunlight. They usually have meetings in the cemetery where there tombstones would naturally be. Amanda and Josh destroyed all the town folk when they knocked over the big tree that kept all the sunlight from getting in the meeting place. The town's folk may not be dead because Amanda thought she saw Compton Dawes (Dark Falls Realtor) at the end when she was sure she destroyed him. They appear in Welcome to Dead House.
- Della River: Formerly a camper at Camp Cold Lake, Della tried to run away from the camp through a forest nearby, but was bitten by a snake and died. She returns from the grave as a ghost, seeking to make one of the other campers become her "buddy" forever. She does so by making them think that she died drowning in a lake, scaring them away from it and instead attempting to flee via the forest, where they will die in the same way she did. She has only succeeded in this plan once; the girl who died returned from the grave in order to stop her from doing it again. She appeared in the Goosebumps book, The Curse of Camp Cold Lake.
- Dr. Aqua: Agent Z's nemesis and the main antagonist of one of the films in Invaders from the Big Screen.
- Dr. Brewer's Clone: During an experiment to electronically combine the DNA of two different plants, Dr. Michael Brewer accidentally cut his hand on a slide and his own blood mixed with the plant DNA. The result was a plant that was part human. Excited by this new development, he continued his work, ultimately creating a plant that was nearly identical to him, but with a few differences. This plant-clone was strong enough and smart enough to overpower its creator, locking him in a closet and taking over his experiments. However, it was not perfect, being forced to sleep in dirt and eat plant food to survive. It also had leaves growing from its head and its "blood" was green. The clone was ultimately killed, cut in two by its axe-wielding creator. It appeared in the Goosebumps book, Stay Out of the Basement.
- Dr. Crawler: A man who accidentally turns himself into a snake. He experiments on children to try to turn himself back. He appeared in the Goosebumps HorrorLand book, Welcome to Camp Slither.
- Dr. Death: An insane entertainer who attends the reader's horror-themed birthday party. He appeared in the Give Yourself Goosebumps book, Scary Birthday to You!
- Dr. Eeek: The mysterious and dangerous chief of Eeek Labs. He appeared in the Give Yourself Goosebumps book, The Deadly Experiments of Dr. Eeek.
- Dr. Fritz Fredericks: Also known as Spidey. Dr. Fredericks stole the camera from his partner to become famous his partner put a curse on the camera making it do the evil things it does today and since everyone would hate him for an invention that predicts bad futures he hid the camera and himself away in the old Coffman house. Dr. Fredericks died of fright when Greg took his picture to escape when he and his friend Shari were forced to stay there forever. He appeared in the Goosebumps book, Say Cheese and Die!
- Dr. Maniac: Robby Schwartz's webcomic supervillain. He appeared in the Goosebumps HorrorLand book, Dr. Maniac vs. Robby Schwartz and in the Goosebumps Most Wanted book, Dr. Maniac Will See You Now.
- Dr. Shreek: A robot created by Mr. Toggle. He is the piano teacher at the piano-learning school. He then tells a student, Jerry, he wants to steal his hands and chases him around until he is shut down and killed by Mr. Toggle. He was introduced in the Goosebumps book, Piano Lessons Can Be Murder.
- Dragons have made appearances in a few books, such as Tick Tock, You're Dead!, The Knight in Screaming Armor , Deep in the Jungle of Doom and Be Afraid – Be Very Afraid!.
- Dwarves: Mischievous creatures who appear in Checkout Time at the Dead-End Hotel. They enslave the reader.
- Egg Monsters: Yellow monsters from Mars who look like egg yolk. They appear in the Goosebumps book, Egg Monsters from Mars.
- El Sydney: A Mexican-themed magician. He appeared in the TV adaptation of Bad Hare Day
- Elvira Martin: A female ghost. Her grave has an angel on it. She materializes inside the house and starts sleeping in a bed for the first time in 81 years. (She probably didn't find her casket so comforting.) She appeared in the Give Yourself Goosebumps book, The Curse of the Creeping Coffin.
- Evil Knight: A suit of black armor containing the soul of a villainous knight. He works for an evil sorceress. He was the one who killed off Sir Edmund Saxton and his family as payback for killing off the sorceress' favorite pet dragon. The reader dons Sir Edmund's armor and defeats the Evil Knight, causing the sorceress to lose her powers and break the curse. He appears in the Give Yourself Goosebumps book, The Knight in Screaming Armor.
- Fifi: The reader's pet poodle in Please Don't Feed the Vampire! If the reader doesn't open the packet of blood-red Vampire Blood, she sinks her teeth into the packet and becomes a ferocious vampire dog.
- Fish Monster: A crazy aquatic beast that the reader turns into after eating a pear enchanted by the Muglani. Depending on which path the reader takes, he or she may or may not end up as a fish monster forever. It appears in the Give Yourself Goosebumps book, Deep in the Jungle of Doom.
- Flying Sharks: Exactly that - sharks who can fly as well as swim. They apper in the Give Yourself Goosebumps book, The Creepy Creations of Professor Shock.
- The Frightener: he is Freddy's uncle who can't get over his fears of clowns, so instead he tortured the clowns by having them fight for survival against a giant mutant squid and a bear and entertain the guests at birthday parties. He appears in A Nightmare on Clown Street.
- Fun House Freaks: People who are twisted and warped as a result of stepping through fun house mirrors. They appear in the Give Yourself Goosebumps book, The Creepy Creations of Professor Shock.
- Gargoyle: Thought to be a statue, this monster attacked a boy named Adam. It attacked him by spitting out green slime that turns anything to stone. It appeared in the short story, I'm Telling! Gargoyles also appear in Shop Till You Drop...Dead!, and in one bad ending, the gargoyles bring the reader and Julie into their world, where humans are used in the same way gargoyles function in the human world, and in Deep in the Jungle of Doom.
- Ghosts: Ghosts are very common in the Goosebumps series. They are the spirits of people who have died and they usually look like when they were alive. They appeared in The Ghost Next Door, Piano Lessons Can Be Murder, Ghost Beach, Phantom of the Auditorium, The Headless Ghost, Ghost Camp and The Curse of Camp Cold Lake. Ghosts also appeared in Headless Halloween, The Haunted Car and Return to Ghost Camp from Goosebumps Series 2000, in several books from the Give Yourself Goosebumps series such as The Curse of the Creeping Coffin and Checkout Time at the Dead-End Hotel and in various short stories.
- Giant Ants: Ants that grew into giants due to being fed incorrectly. They appeared in the short story, Awesome Ants.
- Giant Mutant Squid: This creature is a giant squid that's been mistaken for a plant. It has tentacles, a gaping mouth with huge, jagged teeth and a bulb-like head. This creature has appeared in A Nightmare on Clown Street.
- Giant Praying Mantises: Giant praying mantis robots that appeared in A Shocker on Shock Street, althrough one did appeared as a real insect in the Goosebumps film.
- Giant Seagulls: Seagulls that ate the infected plankton and turned into giants. They appeared in the Goosebumps book, Deep Trouble II.
- Glory: The ghost of a horse that the reader can encounter if he/she chooses to investigate the sounds coming from his/her grandmother's attic. Glory's tombstone describes him as being "too wild for the riders of this world", which could imply that he was put down. Glory is depicted as being temperamental, by stomping on the attic stairs and frothing at the mouth. In one ending (in which the reader dies) it is revealed that Glory can pass through solid objects. He is somehow affected by a remote control in one ending, and doesn't fit into the message used to complete this book properly. Appears in The Curse of the Creeping Coffin.
- Granny Kapusta: A witch who appears in Under the Magician's Spell. She gives the reader a glass of milk and freezes them in place, or else turns into a werewolf and eats them up.
- The Grool: A living sponge creature that feeds on despair. It appeared in the Goosebumps book, It Came from Beneath the Sink!
- The Great Gargantua: Gigi for short. The Great Gargantua is a monster held captive in the theme park HorrorLand and was used to put on shows before she escaped. She is from Goosebumps HorrorLand The Video Game.
- The Haunter: was the name given to the ghost of Benjamin Marple. The Haunter has the power to control the minds of humans and make them act wildly. The ghost appears in the book The Haunter.
- The Haunted Camera: A magic camera with horrifying results was found in the abandoned Coffman House. If someone makes a photograph, it shows the scariest part of the photographed thing or person. This future will always be bad and is more often than not the curse from the camera itself. The Haunted Camera appears in Say Cheese and Die!, Say Cheese and Die - Again! and in the Goosebumps HorrorLand Book, Say Cheese - And Die Screaming!
- The Haunted Car: A possessed, silver-painted sports sedan with white-leather seats and a V8 engine. It was once the property of the Douglas family in the town of Forrest Valley, until teenage daughter, Becka Douglas crashed it during a joyride, in which she was killed. Her ghost took hold of the car and tried to use it as a weapon against those around her, forcing her father to keep the car locked up tightly in its garage until a new owner was found. The Haunted Car appears in The Haunted Car.
- The Haunted Mask: A real living face, one of many who searches for a new body to wear as its own. Originally, the mask was beautiful, but it decayed and became a dangerous monster, along with the other faces that were created by the same person. This happened because while the masks could hide his ugly face, they could not hide what he really felt: ugly. If someone puts the mask on, it cannot be removed, except with a symbol of love or kindness. The Haunted Mask appears in two Goosebumps books, The Haunted Mask and The Haunted Mask II. and the Goosebumps HorrorLand novella The Scream of the Haunted Mask. It also appears in the Goosebumps Most Wanted Series, Wanted: The Haunted Mask.
- Himalayan Snow Wolf Mask: This mask looks like a Himalayan wolf. However, once you put it on, you'll be transformed into a wolf. This mask appears in The Five Masks of Dr. Screem.
- The HorrorLand Horrors: The employees of the HorrorLand Theme park. They are reptilian like monsters. Originally hired by HorrorLand's founder because their monster costumes looked so realistic, he later realized their "costumes", with green skin, yellow eyes, sharp fangs and long tails, were not costumes at all! Originally, they deflated if pinched. However, by the time of Goosebumps HorrorLand, the Horrors have found new ways to become 100% pinch-proof. The Horrors originally appeared in One Day at HorrorLand, reappearing in the game Escape from Horrorland and related media, the Goosebumps Series 2000 book Return to HorrorLand, and most recently as main villains for the entire series Goosebumps HorrorLand.
- Humanigators: Mutated humanoid alligators created by Dr. Aqua. They appear in Invaders from the Big Screen.
- The Ice Hound: A wolf-like creature who resides in the Frozen North. It appears in one of the virtual reality games in the Give Yourself Goosebumps book, Zapped in Space. In one bad ending, it feeds Andy and the reader to its puppies.
- The Ice Vampire: A vampire made out of solid ice that survives by draining the internal heat from human beings, thus turning them into ice in the process. Appeared in the short story, The Ice Vampire.
- Inspector Cranium: Inspector Cranium is a detective with the most notable features are his large head that seems too big for his body and his scalp glows like a light bulb under lights. He is not much taller than some kids and has tiny, round black eyes, a long bent nose, thick gray eyebrows, a small gray brush of beard on his chin and a gold tooth that glows when he is smiling, he appears in the Goosebumps Horrorland Help! We Have Strange Powers! and The Streets of Panic Park.
- Infected Plankton: Laboratory plankton gone horribly wrong. They appear in Deep Trouble II and identified in its TV adaption as "D-13".
- Insect Mask: This mask is colored olive green, has a face of a grasshopper, it has wiry antennae on top of the smooth green head, tiny black eyes, and an open mouth with a stringy black forked tongue. It appeared in The Five Masks of Dr. Screem.
- Izzy Wicked: This demented doctor is the owner of the Wicked Wax Museum.
- Jenna: A genie (dressed more like a punk rocker than a stereotypical genie) who emerges from a Coca-Cola can. With each wish she grants, her appearance changes into a more corrupted being, and each of her wishes have difficulty in turning out the way one would expect. She appeared in the Give Yourself Goosebumps book, Scream of the Evil Genie, and has a cameo in Checkout Time at the Dead-End Hotel.
- John and Jane, the Luckmeyer twins: Two ghosts of twins. They appeared in the Give Yourself Goosebumps book, The Curse of the Creeping Coffin.
- Jonathan Chiller: A man who trapped six children Meg, Marco, Ray, Jessica, Andy, and Sam. He made them play a game that risked their lives. He appeared in The Horror at Chiller House and is the main villain of the second Goosebumps HorrorLand arch of books.
- Karl Knave: A miniature toy who created a miniature toy town called Karlsville. He is full of himself. He sucks children into his toy town and would turn their interests against them. For example, Todd Erikson always wanted to win a prize, like the lottery. When he gets to Karsville, he has won something -- a chance to become a citizen of Karlsville. That means he has to be turned into a plastic toy, forever. Appeared in the mini-series, Goosebumps: Chillogy (1998). Portrayed by Daniel Kash.
- Katrina the Keeper of Cats: A cat woman who is trying to find someone new to be the next Keeper of Cats. She is the primary antagonist in Night of a Thousand Claws.
- Keith: A monster boy who can turn himself inside out, and lives with his mother in the basement of a boy named Marco. Appeared in I Live in Your Basement!
- King Buthramaman: The last great Ruler of Egypt. He was entombed because he bore a strange birthmark. The shape of the birthmark frightened the Egyptians, for they believed it was an evil sign. Every night, his spirit writes in his diary. Whichever route the reader takes will affect how Buthramaman interacts with the reader. He appears in Diary of a Mad Mummy.
- King Jellyjam: A grotesque, purple behemoth who wears a gold crown, with snails dripping out of his skin and an awful stench. King Jellyjam brainwashed innocent men and women to run King Jellyjam's Sports Camp, a summer camp for children who participate in athletic events. Those who win the events are given gold coins called King Coins, and those who win six coins are allowed to join in the Winner's Walk. The truth is, these children are made his slaves, who are forced to wash him nonstop because he cannot stand his rotting stench. If any of the children stop to take a break, they get eaten. His scheme was eventually stopped by a girl named Wendy, who convinced the children to stop washing him and lay flat on their stomachs. Jellyjam could not pick up the children, or any of their hoses, because his fingers are too fat, and he chokes on his own stench. The counselors are snapped out of their trance the minute Jellyjam dies, and the truth is discovered by the police of a nearby town who were searching for the source of the foul stench. Appeared in The Horror at Camp Jellyjam. Also of note, Milo the Mutant, from Little Comic Shop of Horrors, is able to take his form.
- King Tuttan-Rha: An ancient Egyptian pharaoh who kept himself alive by feeding on the preserved innards of the mummies he kept locked up. He appears in the Goosebumps HorrorLand book, Who's Your Mummy?
- Lake Monster: A mysterious creature living at the bottom of Woodsworld lake. It appeared in the Give Yourself Goosebumps book, Night in Werewolf Woods.
- The Lanx: A close relative (and a more dangerous one at that) of the Grool. Appears in It Came from Beneath the Sink!.
- Lava Lizards: Ever since Mount Kenalua started erupting, the volcanic grounds have been crawling with these Lava Lizards. Their lava-colored skin allows them to blend in with the molten rock, which allows them to hide themselves from the eyes of any trespassers. They appear in the book, The Twisted Tale of Tiki Island.
- The Lawn Gnomes: These creatures are actually Mischief Elves, beings who love to cause trouble. They can enter a trance willingly in order to go into an unmoving state (in which they are mistaken for lawn gnomes), then awaken at night in order to wreak havoc. However, they can be forced into their unmoving state again by extremely high-pitched sounds, such as that of a dog whistle. They appeared in the Goosebumps books, Revenge of the Lawn Gnomes and Planet of the Lawn Gnomes.
- Lefty, Righty, and Slim - These three conjoined characters were the mascots for the Goosebumps Triple Header series. Lefty is the joker, Righty is the smart one, and Slim (the middle head) is the leader.
- Lord High Executioner: An executioner who works for the evil uncle of Princess Susannah and Prince Edward. He has executed everyone from the common criminal to the parents of the Princess and Prince, and has the complete trust of their uncle. He appears in the Goosebumps book, A Night in Terror Tower and the Give Yourself Goosebumps book, Return to Terror Tower.
- Loreo: A monster who appears in The Creepy Creations of Professor Shock. It resembles a furry crocodilian, and it likes to eat kids. It is also the announcer of a Fun House Freak Contest.
- Lost Legend: A scrap of parchment that brings ill fortune to anyone who finds it. It says, "Whoever owns the Lost Legend will be lost forever." After Marissa and Justin Clarke find it, they lose their sense of direction. It appears in the Goosebumps book, Legend of the Lost Legend.
- Lucy: A young camper from Camp Spirit Moon who turned out to be a ghost. She appeared in the Goosebumps book, Ghost Camp.
- Madame Doom: A mysterious fortune-teller in Horrorland. She appears just in the Goosebumps HorrorLand book series (such as Help! We Have Strange Powers!) and on the EnterHorrorLand Website. The inspiration for her was the witch Clarissa from the Goosebumps book, Be Careful What You Wish For....
- Maddy Simon: Her and her friends tried to find out if Helga Nuegenstorm was a vampire. At the end of the short story, A Vampire in the Neighborhood, she and her friends turned out to be vampires.
- Maggie: A magic crow. Iris, a witch and employee of "Revenge R Us", needs her to cast spells. This happens by closing the eyes, thinking of the spell and stroking Maggie three times. She has a sister named Minnie. Maggie appears in Revenge R Us.
- The Magician: The evil owner of a magic shop. He will make your sister disappear or use your heads for his shrunken head collection. The Magician appears in the Give Yourself Goosebumps book, Under the Magician's Spell.
- Mannequins: Usually for displaying clothes, these figures are dressed to kill and seek nothing more than to dismember the reader. They appear in Shop Till You Drop...Dead!
- The Masked Mutant: A comic villain that can shape shift into anything solid, but if he turns into a liquid, he can't change back into his original form. Appeared in Attack of the Mutant and also in the video game version of the same name.
- Mary-Ellen: an evil doll from Bride of the Living Dummy.
- Max Creeper: The son of E. Ville Creeper, Max runs his father's botanical gardens. He appears in You're Plant Food!
- The Menace: The owner of Panic Park. This two-faced man tries to trap all the VSG's in Panic Park forever to bring Panic Park back from 1994. Appeared in The Streets of Panic Park.
- Mechanoid: The mechanoids are robots that are created by the lawn gnomes. mechanoids are designed for doing the lawn gnomes' work during the day time. The only way to tell if a person is a mechanoid when is if the mechanoid malfunctions. It appears in Planet of the Lawn Gnomes.
- Milo: A strange looking man, with a warty face, who owns a comic shop in a mysterious alleyway. He is actually a monster from a cancelled comic book series, that has somehow been brought to life. His mission is to trap children in the basement under his store, and keep them there as he tests out various ways to scare them, so he can eventually create a new series. He is apparently able to scan a person's mind to see what they are most scared of, and then become that thing (this leads to a reference to another Goosebumps book). Appears in Little Comic Shop of Horrors.
- Mittens: A mechanical Doberman who appears in Toy Terror: Batteries Included. He was manufactured by the Hasley Toy Company and actually has some of the same features as a real dog (such as salivation). He seems to have a habit of attacking people's legs.
- Monty's Clones: Monty's clones are determined to get rid of the original Monty so that one of them can replace him. The clones first appeared in the Goosebumps Series 2000 book I Am Your Evil Twin.
- Monsters: A bunch of lizard-like aliens hatch out of eggs and only Michael Monroe sees it. If someone drink the yolk you turn into one. Michael's teacher and principal were one also. He eats eggs made out of the yolk and turns into one. Then he eats a little eggs which worked half way. He throws his teacher and principal into a much larger one and they drown. Then the remaining monsters eat some eggs and turn into yolk. They appeared in My Friends Call Me Monster.
- Monster Blood: A green, slimy substance that slowly expands to a great size when released from its airtight container for the first time. In the first book, Evan and Andy's specific batch of Monster Blood seems to have been cursed by an evil witch, but several more cans appear in sequels, confusing the issue. Though it is sold as a child's plaything, both in cans (as in Monster Blood, Monster Blood II, and Monster Blood III) and in plastic egg-shaped containers (as in the Goosebumps HorrorLand book, Monster Blood for Breakfast!), the Monster Blood is a living, evil entity, capable of attacking people if they are close enough (Evan Ross is almost drowned in the bathtub containing Monster Blood). In addition to its growth properties, any biological creature that consumes Monster Blood will slowly grow to monstrous size (which is the main plot point in Monster Blood II and Monster Blood III). It comes in the original variety, which is labeled as a "Surprising Miracle Substance!" (as seen in the first three books), a twelve-hour sample version (as seen in Monster Blood For Breakfast!), and a "new and improved, longer-lasting" Monster Blood, as advertised on the packaging for the "Sample" version. Monster Blood is also used and mentioned in the Give Yourself Goosebumps series, in the book Escape from the Carnival of Horrors, and shown on TV in the Goosebumps Series 2000 book Return to HorrorLand. There is also another kind of monster blood. This slime is blue instead of green and it does not grow, it is multiplying into dangerous blue creatures with sharp teeth. This special monster blood species only appears in Monster Blood IV.
- Mortegarths: Ghosts who are relatives to Drew Mortegarth who all died in Room 402. After they died, the turned into ghosts and started to haunt the entire hotel. They appeared in the Give Yourself Goosebumps book, Checkout Time at the Dead-End Hotel.
- Mr. Baargh: He is a huge, two-headed ugly monster. He appeared in Creature Teacher: The Final Exam.
- Mr. and Mrs. Dark: Lucy's parents who appeared in The Girl Who Cried Monster. It is they who are really weary of Lucy's monster stories. They provide the fuel for the story to progress. First, they ignore Lucy's claims that she has seen a real monster. Second, they decide to invite Mr. Mortman to dinner after Lucy attempts to capture him on a camcorder wherein he did not cast a reflection. Finally, the parents provide the surprise ending to the story; they are monsters, too. And the reason why the parents invited Mr. Mortman for dinner was because he was the "dinner" all along. Note that unlike Mr. Mortman who needs to eat insects to provide stimulation for his transformation, the parents can transform at will. They reveal to Lucy and Randy that they are not "fully" developed, but will eventually grow to be a monster just like them. In the book, they only grow fangs. But in the show, they grow fangs, and then they have reptilian features.
- Mr. Grimsley: A summer school teacher who locks children in a chalk closet depending on how bad they have been. Appeared in a short story, The Chalk Closet.
- Mr. Knowledge: A character appeared in Under the Magician's Spell. He tests people to see if they can find a red ball under one of three identical cups. If anyone accuses him of cheating, he gets mad and turns into a monster.
- Mr. Mortman: The creepy librarian and villain of The Girl Who Cried Monster. No one knows that he can transform into a monster until Lucy inexplicably stumbles upon his transformation because she forgot her roller blades. Note that Mr. Mortman can only transform into a monster if he eats crickets and other insects. His eyes bulge out while the top half of his head has bubbly and slimy skin.
- Mr. Wood: An evil living dummy that can be brought to life by saying "Karru marri odonna loma molonu karrano", which means "You and I are one now". He was eventually destroyed by getting crushed by a road roller. Appeared in Night of the Living Dummy.
- Mrs. Maargh: A monster in teacher disguise. At the end of each term, she eats children depending on how bad they have been. Mrs. Maargh appears in Creature Teacher and Creature Teacher: The Final Exam.
- Mrs. Forster: A woman who changes into a spider to get revenge on a child named Shawna when she broke a china bowl. She kept appearing everywhere. Appeared in a short story, Home Sweet Home.
- Mud Monsters: Not much information is known about these creatures made of mud. They appear in You Can't Scare Me!
- Muglani: A tribe of witch doctors who have a strong dislike for humans (even though they themselves are human). They seek to turn any and all humans into animals or monsters. Or shrink their heads. They appear in Deep in the Jungle of Doom.
- Mummies: Mummies appeared in The Curse of the Mummy's Tomb and Return of the Mummy. They also appeared in the Goosebumps Series 2000 book The Mummy Walks, in several Give Yourself Goosebumps books such as Diary of a Mad Mummy and in various short stories.
- Mummy Mask: This mask looks like the face of a mummy. Its eyes are sunken, and the wrappings around it appears torn and stained. It appears in The Five Masks of Dr. Screem.
- Murder the Clown: there are two versions, Murder the Clown (Jonathan Chiller) from When the Ghost Dog Howls and The Horror at Chiller House and Murder the Clown (Uncle Theo) from A Nightmare on Clown Street.
- Nasty Kathy: A living doll with a rude attitude. Nasty Kathy wears a pink dress and shoes and has pigtails, blue (or red) eyes, and two rows of small, sharp teeth. She says all kinds of insults, slam-downs, and nasty cracks to anyone she meets. Nasty Kathy runs the Hasley toy factory after hours. She is one of the villains in the Give Yourself Goosebumps book, Toy Terror: Batteries Included.
- Count Nightwing: A vampire summoned from opening a bottle of Vampire Breath. He goes after Freddie and Cara. In the end, Freddie's mother recognizes Count Nightwing as her father. He appeared in the Goosebumps book, Vampire Breath.
- Nick: A reptile friend that appeared in the Give Yourself Goosebumps book, Trapped in Bat Wing Hall. In one ending, he nips the reader's head off.
- Night Crawler: In the Give Yourself Goosebumps book Deep in the Jungle of Doom, the reader accidentally bumps into a carnivorous night crawler within a cavern tunnel. The night crawler then eats the reader alive.
- Nighthawk: An armored bird that appears in The Knight in Screaming Armor. They are in league with the Evil Knight and the Sorceress for whom he works. They snatch up victims and take them away to their nests, where eggs form around the victims. It is unknown exactly when these eggs hatch out, but it can be speculated that the victims become Nighthawks themselves when they do. The reader's cousin Abbey becomes a Nighthawk at a certain point in the story, depending on which route the reader chooses.
- Nila Rahmad: Prince Khor-Ru's thousands-year-old sister posing as a journalist. Her goal is to reanimate her mummified brother to reign with him again. She appears in the Goosebumps book Return of the Mummy.
- Norband: A headless zombie child who appears in Headless Halloween. He hears about what Brandon did and makes him put right all of his wrongdoings. When Brandon's time is up, Norband reveals that he never intended to let Brandon live.
- The Nutcracker: In the short story Nutcracker Nightmare, this play is actually a spell placed upon the audience.
- Octopus: A menacing mollusk the reader encounters in The Twisted Tale of Tiki Island.
- Officer Murphy: A life-sized toy police officer created by Nasty Kathy. How he interacts depends on which route the reader chooses. In one ending, when the reader agrees to help out the toys, he puts on an assembly at school and uses the reader as a demonstration doll. He appears in Toy Terror: Batteries Included.
- Pinky Flamingo: A mobster who appeared in the video game Attack of the Mutant. He has a grey Mohawk, squinted eyes, large expressive teeth, and wears a flamingo-pink zoot suit. He is armed with ten deadly digits. On his right hand, he has a screwdriver, a drill, a mallet, a chisel, and a sharpener. The other five digits are erasers, which he can use to rub out anything. The player defeats him by spraying him with a fire hose, causing him to swell up and burst.
- Mutant Plants: Mutated plants that appear in books such as Stay Out of the Basement and You're Plant Food! They consist mainly of vines or tendrils and carnivorous plants. Some of them are even venomous.
- Poltergeist: A ghostly figure who resides in Escape from Horror House. It can possess anything or anyone it chooses, turning them into monstrous beings.
- Pomeranian Dogs: Close relatives of the Keeshond, these are two Pomeranian dogs that were featured in the (fictional) movie that was filmed at Payne House. In the movie, they could change from normal dogs into monsters, and the reader finds that they can also do this in real life. They appear as antagonists many times, and are the cause of many endings for the reader. They are also seen on the front cover of the book. These vicious demonic dogs appeared in One Night in Payne House.
- Priestess Khala: A priestess who puts a horrifying "curse" on her chamber. She appeared in The Curse of the Mummy's Tomb.
- Prince Khor-Ru (book 23, Return of the Mummy): A mummy who was brought to life when Gabe recited the chant "Teki Kahru Teki Kahra Teki Khari" five times. He now sought to make people living mummies, like himself.
- Professor Shock: An inventor whose workshop is found in a new part of town. He requests that the reader, Jason and Stacey help to clean out his garage. In the back room is a robot, a remote control, and a pinball machine that leads to a mirror wonderland. He alternates between good and evil depending on what storyline the reader takes part in. He appears in The Creepy Creations of Professor Shock.
- The Pumpkin Heads Fire breathing pumpkin headed creatures that are actually shape-shifting aliens that eat overweight adults. They appeared in Attack of the Jack-O'-Lanterns.
- Puppet People: the puppet people are three normal marionettes (the king, the knight, and the princess) that move on there own, also they have this curse that whenever touch a victim by the ear that victim gets slowly transformed into a marionette, they appeared in Night of the Puppet People.
- Purple Rage: A super villain from an online comic created by Robby Schwartz. He appears in Dr. Maniac vs. Robby Schwartz and Dr. Maniac Will See You Now.
- Phantom of the Auditorium (character): A phantom that haunts an auditorium. He tries to stop a play that he was in, but died before he started. He dies again when he falls down a trap door. He appears in Phantom of the Auditorium.
- Purple Peanut Butter: A jar of purple goo that has a texture similar to peanut butter. The reader finds it stashed away in an old refrigerator in Aunt Fiona's basement. Its flavor is described as "a combination of every delicious dessert you've ever had" -- but only if the reader chooses it first. Otherwise, it'll taste awful, like brussels sprouts, broccoli, and liver. After the reader eats it, they slowly start to shrink. Depending on which route the reader takes, they face one of several different perils, such as fighting a giant mouse, getting chased by a giant Puff the cat, being swept into the sewer systems, ending up in a junkyard, or simply shrinking down to nothing. This substance appeared in the Give Yourself Goosebumps book, Beware of the Purple Peanut Butter.
- Q Quest Players: Monsters who play the game Q Quest in Return to the Carnival of Horrors. They try to see to it that you lose.
- Queen of Nightmares: A strange-looking queen with bird-like features who appeared in The Creepy Creations of Professor Shock. She is the ruler of the Mirror Wonderland that the reader and her friends, Jason and Stacey enter. She has numerous stone carvings hanging in her chamber, and a large looking glass that shows and tells her all she needs to know.
- Rat Man: A villain from a video game, Mortal Revenge. He is a four-armed ninja fighter, with the head, tail, and other features of a rat. He carries a sword in each hand. The reader encounters this foe when they wish (granted by Jenna the Genie) to do the video game in real life and are zapped inside. But the reader is unable to beat him, even when they start to make a wish from Jenna. It is said that he's the most horrifying warrior in all of Mortal Revenge. He appears only in Scream of the Evil Genie.
- Rat Monster: A monstrous rat of unusual size. It attacks the reader and grabs them by the throat. It appears in Under the Magician's Spell.
- Rattlesnake: A giant diamondback rattlesnake with mystical powers. It has the ability to change people into anything it chooses. How it approaches the reader depends on which path they choose. This magical rattlesnake appears in Alone in Snakebite Canyon.
- Ray: One of the dead children in Dark Falls. Ray is the watcher who watches and pretty much spies on the new families. Ray seems to like baseball and plays a lot with Josh and Amanda. Ray's skin melted off when Josh accidentally pointed his flashlight at him. Ray may be dead, but it could be the same deal with Compton Dawes, whom Amanda thought she saw at the end when they drove away. Ray appears only in the first Goosebumps book, Welcome to Dead House.
- Reflections: These evil entities want to replace everyone who turns on the light put on the top of the mirror they wait in. It turns people invisible, when the light is turned on. If invisible wait too long, the reflections will replace people and they will come out leaving the people in floating bubbles forever. To save them, you must destroy the mirror with them on the shattered glass. They appear in the sixth Goosebumps book, Let's Get Invisible! Also, in the Give Yourself Goosebumps book, The Creepy Creations of Professor Shock, the reader's own reflection trades places with her or him when a mirror is shattered or being end up fleeing from her or him in terror. An evil reflection also appears in the short story Mirror Mirror on the Wall.
- Reggie Mayfield: A boy who tells you that there are monsters in his dad's store, Mayfield's Bazaar. At midnight, it's revealed that he is cursed and transforms into a hulking mutant during this time. If the reader chooses the right path, they will end up lifting the curse and restoring Reggie to normal. If not, something bad will happen to the reader (such as getting eaten). Reggie appears only in the Give Yourself Goosebumps book, Shop Till You Drop...Dead!
- Rip: An undead cat who is named after the abbreviation for Rest in Peace: RIP. If Rip loses one of his nine lives, he looks for new victims, that can spend him theirs. If Rip scratches someone, a bit of their life comes over him. The scratches of Rip glow strange before they heal quickly. People that get scratched by him transform into cat-like creatures. Rip appears in the first Goosebumps Series 2000 book, Cry of the Cat. Rip is very similar to the cat Misty, that appears in the short story, The Cat's Tale.
- Robots: Mechanical machinations that may or may not be humanoid in appearance. They have appeared in a number of books, such as Piano Lessons Can Be Murder, The Creepy Creations of Professor Shock and Tick Tock, You're Dead!
- Robot Arm: A giant, metallic robot arm found in the Space Travel Room. Its hand is big enough to crush anything, even your skull. It appeared in Into the Jaws of Doom.
- Robot Zookeepers: These machines are the keepers of a human zoo in Tick Tock, You're Dead! The reader is captured by them and placed in the "Couch Potato" exhibit.
- Root Rot: A plant-like being who appeared in the video game Attack of the Mutant. He is capable of controlling plants and summoning vine tendrils to do his bidding. But he doesn't really show much in the ways of intelligence. His domain is a greenhouse with a hedge maze. He is later defeated when the player knocks him backwards into a fan.
- Roses: Mutant alien roses appearing in Secret Agent Grandma. They have many similarities to Earth roses, but are in different colors, have different scents, and even glow in the darkness. The hostile ones have eyes and an ugly mouth, and have thorny tendrils to grab anybody. Also, they can choose to gobble up their victims (such as a taxi driver) or spit orange goo on them, which mutates them into roses. They also make an appearance in You're Plant Food!
- Sadler Ghosts: The ghosts of three young siblings (Sam, Louisa and Nat Sadler) who died in 1641. They appeared in the Goosebumps book, Ghost Beach.
- Sarabeth: An evil sorceress who appears in the book Monster Blood. She took on the appearance of a black cat and had since been living with Evan Ross' aunt, Kathryn. She is defeated when Evan's dog, Trigger knocks her into Monster Blood and is consumed by the substance.
- Scarlet Starlet: A webcomic character made by Robby Schwartz. She teams up with Dr. Maniac in the Goosebumps HorrorLand book, Dr. Maniac vs. Robby Schwartz and Dr. Maniac Will See You Now.
- Scarecrows: A bunch of scarecrows that were brought to life by a girl's cousin named Stanley. He did it by chanting magic words. The scarecrows were defeated by his son Sticks when he used torches to light them on fire. They appeared in The Scarecrow Walks at Midnight.
- Shape-shifting Lizards: these lizards can shape-shift, but at the moment they are hatched from an egg they look like kids, and once they are older (say like 12) they eat meat and insects, have a scaly skin, and starts to walk like an actual lizard plus they might relax in sunlight or taking a nice hot shower, but by the time they are an adult they look like a humanoid (that's because it was balanced standing on its two hind legs and its fat tail) scaly-green lizard that is about 6 ft tall, has a warty head and a purple tongue, so the main protagonist and her dad are the shape-shifting lizards in The Lizard of Oz.
- Shrunken Head: A green head which was given to Mark by his Aunt Benna in How I Got My Shrunken Head. The head grants him mystical powers.
- Skeletons: The living skeletal figures who have appeared in a number of books. Curly the Skeleton is perhaps one of the most well-known appeared in Tales to Give You Goosebumps.
- Skull Mask: This skull mask has is a whitish-yellow color. It has deep eye sockets, an open jaw, a hideous toothy grin, and cracks criss-crossed atop its head. It appeared in The Five Masks of Dr. Screem.
- Slappy: A famous evil living dummy that was carved from a cursed coffin by an evil sorcerer in the late 1800s, and can be brought to life and put to sleep by saying "Karru marri odonna loma molonu karrano", which means "You and I are one now". Appeared in Night of the Living Dummy, Night of the Living Dummy II, Night of the Living Dummy III, Bride of the Living Dummy, Slappy's Nightmare, Revenge of the Living Dummy, Dr. Maniac vs. Robby Shwartz, Escape from the Carnival of Horrors, The Streets of Panic Park, Slappy New Year! and Son of Slappy as well as the stage play Screams in the Night and his very own series, "Goosebumps SlappyWorld". He is also the main antagonist in the Goosebumps film where he's voiced by Jack Black, who also played R.L. Stine and voiced Brent Green from My Best Friend is Invisible.
- The Snake Lady: A snake-like lady who appeared in Escape from the Carnival of Horrors. She is one of the exhibitions int he carnival's Freak Show. She is described as a yellow haired woman with a serpentine body, however, if the reader encounters her, she is inexplicably changed to a human lady, with actual snakes wrapped around her. The good news is, she tells the reader where they are. The bad news is, she fools the reader.
- The Snatcher: a shape shifting ghost from Return to Ghost Camp. it can take the form of anything it wants, and it snatches the campers of Camp Full Moon.
- The Snowman: A demon accidentally created by a wizard named Conrad and his deceased wife. They transformed it into a snowman with a scar on its right cheek, and then trapped it inside a mountain cave in the town of Sherpia and the only way to free it is by reciting this poem "When the snows blow wild, And the day grows old, Beware, the snowman, my child. Beware, the snowman. He brings the cold. When the snows melt And the warm sun is with thee, Beware, the snowman --- For the snowman shall go free!". Appeared in Beware, The Snowman.
- The Sorceress: A wicked practitioner of magic in The Knight in Screaming Armor. She got angry at Sir Edmund Saxton after he killed off her favorite pet dragon. As payback, she crafted a suit of black armor and possessed it with the spirit of a villainous knight, which came alive during the night and killed off Sir Edmund and his family (except for one son, who had been out hunting at the time). The reader confronts the Sorceress in her domain, and (if the right path is chosen) defeats the Knight. It seems the Evil Knight is somehow connected to the Sorceress' powers, because after the Knight is defeated, the Sorceress loses her powers.
- Special Agent Bendrey: A secret agent who appears in the book Secret Agent Grandma. Depending on which route the reader chooses, he may be friendly or hostile. At one point in the story, he reveals that he doesn't investigate aliens. Instead, he is an alien who investigates.
- Splatters: Super-intelligent insect creatures trying to take over an alien planet in Earth Geeks Must Go! They are so-called because they are balloon-like and are easily popped, through physical pressure or high-pitched noises.
- Spyder: A computer virus that appeared in It Came from the Internet. It erases people's memories, and the reader must find a away to delete it before it causes havoc.
- Stone King: The ruler of a forgotten race of cave people discovered in Deep in the Jungle of Doom. When the reader and her/his friend Zoe happen open the king and his clan, he gives them a timepiece and tells them to retrieve gold nuggets for him. Depending on which way the reader chooses, the king may slip something into your food so you become like them, turn you into stone for stealing his timepiece, or reward you handsomely for completing the task.
- Stone People: A long-forgotten race of cave people encountered in Deep in the Jungle of Doom. They have large eyes, heads with green mossy hair, and bodies covered with rock-like scales.
- The Strangler: A wax figurine of a serial killer who strangles the life out of his victims. Appeared only in Welcome to the Wicked Wax Museum.
- Super Computer: An evil computer who takes over the whole Hall of Incredible Science and manages to destroy the reader. In one point of the story, the Super Computer takes the form of the dragon. The Super Computer appears in Into the Jaws of Doom.
- Susie Snowflake: The sickeningly sweet heroine from a cheesy Christmas movie called, A Holly Jolly Holiday, which is available on a cursed video with weird results that brainwashes anyone into looking and acting like her. Seen in the Goosebumps short story, A Holly Jolly Holiday. Possibly inspired by the popular Christmas song of the same name.
- Swamp Monster: A member of a race of swamp creatures, living in a swamp in southern Georgia. The creature is described as being almost ten feet tall, resembling a gorilla, but with a reptilian face and jaws, and with vines tangled in its fur. It wandered into the home of an elderly couple, who trapped it in one of their spare rooms. It stayed there for a few weeks, being fed by its captors, until it was accidentally freed by their granddaughter Gretchen and her stepbrother Clark. After escaping, the monster attempted to eat them, but when it tasted Gretchen, it revealed it could talk, and that it was allergic to humans, after which it dropped dead. It appeared in How to Kill a Monster. There is also another Swamp Monster in Escape from the Carnival of Horrors, but is mistaken for a costume.
- Sybil Wicked: A living wax figure. She was the most beautiful creation of Dr. Izzy Wicked. But her original face was burnt off by a fire, and she now seeks to replace it with someone else's. She currently has a patchwork face over her creepy-crawly infested one. A bunch of wax figures that look just like her are stashed away in a private storage room. She becomes angry after the reader ruins them, and seizes them to try and remove their face with a machine called the "Face Lifter". When she gets too close to a Suction Screen, her patchwork face comes off. If the reader doesn't have a mirror on them, Sybil steals her or his face. If they do, Sybil melts after seeing her own hideous reflection. Sybil appears in Welcome to the Wicked Wax Museum.
- Talking Animals: Animals who are capable of intelligent speech. They appear in the Give Yourself Goosebumps book Into the Twister of Terror.
- Three-faced Clock: A futuristic clock that Kip, Abbey and the reader find in a museum in The Knight in Screaming Armor. This square diamond-shaped clock face has a shimmering chrome frame and has three smaller clock faces on it. One face is round, silvery green, has wavy silver hands, and turns time backwards. Another is round, hot pink, has straight black hands, and moves time forwards. The last one is fiery orange, shaped like an octagon, has no hands at all, and stops time cold. Turning the hands on the green clock face ends up with the reader and their cousins getting turned into babies. Turning the hands around on the pink clock face will result in the reader and their cousins getting turned into elderly citizens. Touching the handless orange clock face results in everyone (and everything) getting frozen in time.
- Three-headed Gardener: An ancient wizard gardener with three ugly heads. If the reader encounters him, they suffer one of three different fates along with their cousins, Kip and Abbey: being turned into birds, becoming flowers in his garden, or merging together into a single three-headed person. This decrepit old gardener appears in The Knight in Screaming Armor.
- Tikis: Living statues the reader encounters in The Twisted Tale of Tiki Island. They are angry with the reader since they have taken the Tiki Eye, their most sacred relic.
- Time Police: A group of police officers whose duty is to ensure that nobody tampers with time. They appear in Danger Time.
- Tongue Thing: This slimy creature from One Night in Payne House resembles a bunch of tongues. How it responds depends on which path the reader chooses.
- Toobah: A wart-covered genie whom the reader may or may not encounter in Scream of the Evil Genie. He has bad breath and moss-coated teeth. If the reader takes his advice, he poofs them back home. If the reader takes chances with him, he summons several rattlesnakes.
- Trap Toys: Inventions of Professor Darius in the Alternate Universe known as Truant. Used to capture children to send them to the prison complex known as "School." Some have been captured by the Children's Resistance Front and reprogrammed to dispose of traitors. Seen in Elevator to Nowhere.
- Undead Ed: Ed the ghoul (a type of shadowy zombie) appears in Lost in Stinkeye Swamp. He got lost in the sewers where he worked and died in the tunnel twenty years prior to the story, and lives in an old work site. He waits for any prey to come his way to feast on them. When a victim comes, his disguise melts off, revealing his true self. He uses a big steel crowbar as a toothpick when he's done, since he still believes in good dental hygiene.
- Undead Pirates: Spanish conquistadors the reader encounters in The Twisted Tale of Tiki Island. Also, in Creep from the Deep Captain Ben and his crew are a group of zombie pirates.
- Vampires: Appear in a number of books, such as Vampire Breath, Invaders from the Big Screen, and Please Don't Feed the Vampire!.
- Vampire Chicken: Freakish blood-sucking chickens the reader encounters at one point in The Curse of the Creeping Coffin. One of them drinks the reader's blood.
- Vampire in a Can: appears in Please Don't Feed the Vampire! It's what the reader first considers to be a cheesy vampire costume. But the reader soon discovers it has a packet filled with actual vampire blood. Anything or anyone who consumes it will become a real-live vampire. If the reader doesn't open it, their poodle Fifi bites on it, and becomes a ferocious vampiric hound. If the reader does, then he or she will become a vampire.
- Vamporilla: A cross-between a vampire bat and a gorilla. Seems to live inside a padded room opposite the waiting room at a laboratory, and is violent enough to kill any intruders, very painfully. It is never revealed how this creature came into existence, but is most likely one of Dr. Eeek's experiments, as other hybrids (such as dog/humans) have been created by him. Seen in The Deadly Experiments of Dr. Eeek.
- Vanessa the Mystic: A mysterious woman who lives on the other side of town. She's a stickler on good manners, and changes anyone whoever doesn't say "sorry" to her. She appears in Chicken Chicken.
- Dr. Vanessa: Dr Eeek's assistant, who informs him of your arrival. She has a spray which can cause people to fall asleep for a long time, possibly forever. She appears in The Deadly Experiments of Dr. Eeek.
- Venus Fly-Trap: An oversized version of its most well-known smaller counterpart. While the smaller fly-traps normally eat insects, this larger fly-trap eats larger-sized creatures - like the reader and their friend Zeke. The reader runs into this plant in the story Lost in Stinkeye Swamp.
- Verona XG-20: While not an actual monster, this universal remote can control everything around it. Appears in the short story Click.
- Victor Frankenstein: Victor Frankenstein is a robot that look's exactly like Kat's uncle, but to tell them apart is that the robotic Victor Frankenstein has a switch on his ankle. Victor appears in Frankenstein's Dog.
- Visible Man: A man with no skin, who is controlled by the Super Computer, and prevents the reader from leaving the third(?) flaw. He's really a science display that has been brought to life, and tends to strangle his victims. He does not have eyelids, so he doesn't close his eyes when he needs to, which is a weakness that the reader should expose. He appears in Into the Jaws of Doom.
- The Vulture's Claw: it looks like an actual claw from the vulture in a form of a good luck charm. It has the ability to make someone who holds it will be very lucky, but if someone kisses it on the who wears it will grant bad luck and it makes them to hallucinate that its alive and see a gray vulture without it's claw. It appears in The Birthday Party of No Return.
- Wartlock is a strange mutant creature who appeared in the video game Attack of the Mutant. His body is coated in yellow bumps, and he has a slightly smaller head near the one on his shoulders. He has enslaved bunches of "toadies" (toad-like creatures) to gather odd fruit for him. He uses a paint gun to vaporize any who mess up. He finally gets defeated when the player uses his paint gun to send him plunging into a poisonous river.
- Weirdo (Bim): An orange alien found by Meg and her brother Chris. He made them give him back rubs. Later on they make him mad, and just before he kills them he sees a toy that was his. He took it and left. Appeared in Weirdo Halloween.
- Werewolves: Monsters who appeared in the Goosebumps books, The Werewolf of Fever Swamp and Werewolf Skin. They also appear on Give Yourself Goosebumps books, Night in Werewolf Woods, The Werewolf of Twisted Tree Lodge, and All-Day Nightmare, in the Goosebumps Series 2000 books, The Werewolf in the Living Room, Full Moon Fever and Jekyll and Heidi, and in various short stories.
- Wicked Clowns appear in Trapped in the Circus of Fear. These unfriendly entertainers either want to turn the reader and their friends into clowns or else kill them in the act.
- Will Blake: A 12 year-old boy who is actually a werewolf. He appears in The Werewolf of Fever Swamp.
- Wind Spirit: A wind elemental being who appears in Into the Twister of Terror. It resides within a twister tornado that picks up the reader. How the Wind Spirit reacts depends on which path the reader chooses.
- Wizard the Lizard: A gigantic lizard in Medieval times. When the reader encounters him, he eats the reader up. Wizard the Lizard's only appearance was in Tick Tock, You're Dead!
- Wolf Boy and Wolf Girl: Two werewolves made for an amusement park. Appeared in A Shocker on Shock Street.
- Worms: Some worms that started torturing a boy named Todd. They started appearing everywhere. Then he found out his sister was tricking him, so he plotted his revenge. Then a giant worm popped out of the ground and grabbed him, but a giant robin (which was really paper mache) scared the worm away. Appeared in Go Eat Worms!
- Xentronians: Aliens who run Camp Running Leaf, who appeared in Escape from Camp Run-For-Your-Life. In some instances, they brainwash the reader, enslave the reader on their planet, or just flat out exterminate humanity.
- Yves Yaboum: Also known as Professor Y, he is the leader of the Y's Guys in Little Comic Shop of Horrors. His hairdo acts like extending tendrils, which he uses against the reader (he thinks that the reader is an evil spy).
- Countess Yvonne: A vampire Countess who appeared in Please Don't Feed the Vampire! The reader may or may not encounter her, depending on which way they take. In one point of the story, the reader licks the blood off of her face and is told to close the book, since it is "not normal to drink blood".
- Zodiacs: An organization of twelve beings, each of whom represent the twelve astrological signs. Depending on the reader's horoscope in real life, they either help you or kill you. These beings appear in the Give Yourself Goosebumps book, Danger Time.
- Zoe is a rat-like hippie who appears in Attack of the Beastly Babysitter. She is working for KidsCare and takes care of you and your brother, "Stinko".
- Zombies: The walking corpses of the dead. They appeared in many of the Give Yourself Goosebumps books, such as Escape from Camp Run-For-Your-Life and Zombie School. They also appear in the Goosebumps book, Welcome to Dead House, in the Goosebumps Hall of Horrors book Why I Quit Zombie School and in the Goosebumps Most Wanted book Zombie Halloween.
- Zorax: A mutant monster who appeared in the video game Attack of the Mutant. The player first encounters him in an elevator. The player backs up into the storage room, but finds a hammer, and throws it at the monster, causing him to break up into several smaller versions of himself. Later, when the player enters the comic room, Zorax reassembles himself. The player finally manages to knock him back into the printing press, shutting it down.
- Zorgs: Monstrous toys who appear in the Give Yourself Goosebumps book, Toy Terror: Batteries Included. They rip up their victims' faces so they can get to their brains.