The Masked Mutant is a supervillain and the main antagonist in the twenty-fifth Goosebumps book, Attack of the Mutant.


Attack of the Mutant

Not much is known about the Masked Mutant's past life. All that is known about him is that he had become the most powerful, male super villain in the world, who had the power to move his molecules around and change into anything solid. With these powers, the Masked Mutant was able to escape from The League of Heroes, including his arch-nemesis named The Galloping Gazelle, who is the leader of the League of Heroes. There has been moments when the Masked Mutant fought the superheroes teams, including when he had SpongeLife, the sponge of steel in a tight squeeze as a giant octopus, but they managed to escape from him every time.

The Masked Mutant was also aware that he was a comic book character and he somehow managed to find his way into the real world, along with the other characters of his world. In the real world, he went out in disguise, looking for people who might be worthy of being new characters for his series, which was not very easy for him. His henchman, The Magnificent Molecule Man also dressed up as him to throw everyone off the track.

One day, the Masked Mutant was out traveling for new faces, disguised as a twelve-year-old girl named Libby by mimicking her voice in order to concealed his identity from a boy named Skipper Matthews. On the bus, Libby (who is actually the Masked Mutant in disguise) meet a boy named Skipper Matthews, who told her that he collects the Masked Mutant's comic book series, which are his favorite comic books. Libby told him that she collects High School Harry and Bean Head comic book series, which Skipper Matthews hugely disliked, creating an argument about which comic books were good and how much they are worth and then Skipper Matthews got off the bus, realizing that he had missed a stop. When Libby and Skipper got off, Skipper saw the Masked Mutant's green and pink headquarters and he recognized it from one his comic books. Libby told him that it was ugly and her father says the architect had to be color blind. She noticed that Skipper was in shock and he told her that he thought he had seen the building somewhere. Libby invited Skipper Matthews to come over to her house, but Skipper Matthews had an orthodontist appointment. The next day, the Masked Mutant went out disguised as Libby again by mimicking her voice in order to conceal his identity and ran into Skipper Matthews, who was astounded to find the building was nowhere to be found and seen. The Masked Mutant told him that she was glad it was gone and asked if he really came to see the building, to which Skipper Matthews lied by saying "no". Libby then invited a frazzled Skipper Matthews to see her comic books, which he agreed to, unaware (until he read The Masked Mutant's next comic book series) that the Masked Mutant had put an invisibility curtain over the building so that nobody will find his secret headquarters.

The Masked Mutant was very intrigued with Skipper Matthews, especially since he knew so much about his comic books, so he thought that Skipper Matthews might be worthy of being a new character for him and started to do some drawings of him. A couple of days later, Skipper Matthews caught up with Libby on the bus and told her that he was going back to the building as he reckoned that there was an invisibility curtain around it. He told Libby about his newest comic book series and that it could be giving him clues as to what was happening in real life. Libby viewed him as crazy and teased him about the comic books coming to life, which angering Skipper Matthews. Never the less, she went with Skipper Matthews to what was thought to be an empty lot, grumbling that she could not believe that she was doing this until they went through the invisibility curtain and saw the building, confirming Skipper Matthews to be right all along. Skipper urged Libby to come with him and they went inside.

Along the way, a beam of yellow light shot out from the wall and shined on Skipper Matthews' body. He asked Libby what that was, but Libby told him she didn't feel anything at all. As they walked through the eerily empty building, Libby accused Skipper Matthews of thinking that this is the secret headquarters of the Masked Mutant, to which he replied that it probably is due to the invisibility curtain. Then the two of them came across an elevator, which Libby was nervous about, but decided to go with Skipper Matthews as he was determined to solve the mystery. But Libby was only coming because she "felt sorry" for Skipper as she thought he was really messed up, thinking comic books can come alive. When they got into the elevator, it speed down into the basement. They attempted to go back up, but the elevator would not cooperate and it closed back up as soon as they got out of it. Libby was most hysterical at this as there were no other elevators did not seem to be any other elevators in the basement. Skipper Matthews suggested that there might be other elevators or a stairway and they started looking around for a way out. Then somehow Libby got separated from Skipper Matthews and looked around for him, managing to find some elevators that are working in the process. She then found Skipper Matthews at a printing press and he told an angry Libby that he found some drawings of himself, but Libby told him that he has a sick imagination and he is weird. They then managed to leave the building and head on home, with Skipper not realizing that the light that shone on him was a scanner that the Masked Mutant had installed, which can make any human into a comic book character by turning them into ink.

Some time later, The Masked Mutant was planning to do evil against the world when the Galloping Gazelle somehow infiltrated his lair to stop him. But the Masked Mutant captured him and locked him away in order to boiled him alive. Then he released another comic book saying that Skipper Matthews is his new foe and he is the only one that can save the Galloping Gazelle and the world. The next afternoon, Libby watched a very hesitant Skipper Matthews go into the Masked Mutant's headquarters and decided to follow him. After Skipper Matthews rescued the Galloping Gazelle, he helped Skipper Matthews battle with the Masked Mutant and was knocked down. Upon the Masked Mutant shape shifting into a leopard, the Galloping Gazelle fled. Libby caught up with Skipper Matthews, who told her to get away. But Libby stood her ground with the Masked Mutant, threatening him with a weapon called a Molecule-Melter. But the Masked Mutant kept on coming, so Libby fired the Molecule-Melter at him and melted him away, killing him instantly.

But then, Libby surprised Skipper Matthews by revealing herself to be the real Masked Mutant and it was the Magnificent Molecule Man she had melted and threatened to do something bad to Skipper Matthews. The Masked Mutant told Skipper that he knew he was perfect when he told him he knew everything about his comics and it was hard to find new faces, which is why he was pleased when he discovered Skipper Matthews. He told Skipper Matthews that he is a comic book character now, revealing what the scanner had done to him when he entered the building. Skipper Matthews argued that he was lying, but the Masked Mutant insisted that he was not lying this time (lying has always been one of his better qualities). The Masked Mutant told Skipper Matthews that he has made his last and final appearance in any comic book series and Skipper Matthews surprised by saying that he is the Colossal Elastic Boy. The Masked Mutant was bent on destroying the boy, but "Elastic Boy" said that nothing can destroy him except sulfuric acid, which the Masked Mutant was happy to hear and he changed into a wave of sulfuric acid to destroy Skipper Matthews. But he did not realize until it was too late that Skipper Matthews had tricked him into changing into liquid and once the Masked Mutant had changed into a liquid, he could not change back. And so, the Masked Mutant, the most evil super villain ever to walk the planet was destroyed.

Video Game

The Masked Mutant is bent on transforming the real world into a comic book. He has constructed a "Green Beam" machine that can convert people and buildings into comic book drawings. When the villainous Mutant encounters the player during the final confrontation, the player destroys a tank of "Slima-Bean Juice" behind him. He is drenched in the green ooze and starts sobbing, as he shrinks away into nothing. Everything affected by the Green Beam reverts back to normal afterwards.

General Information

Physical appearance

The Masked Mutant was a tall and powerful-looking man. He wears a dark blue and orange costume, cape and mask. In the video game, his suit is dark purple and yellow, and he has yellow lenses over the eye holes of his cowl.


The Masked Mutant acted in just the way the classic supervillain would act. He was deceitful and sadistic and he was really bent on world domination and he was the most fearsome supervillain ever created. He was very sneaky, considering that he was able to hide from The League of Good Guys with his power to transform into anything solid and he was always determined to annihilate his arch-enemies and he hated it when any of them interfered with his plans. And he was very capable of lying and he bragged that it was one of his better qualities. The Masked Mutant was always determined to find new faces, good characters for his stories, to find good foes for his stories (it could be an indication that he was bored with fighting the same arch-enemies over again). But he would always be sure that it would be over for his new foes as well. The Masked Mutant may have been evil, but he had a tendency to underestimate his enemies, which did lead to his downfall.


The Masked Mutant was a comic book villain with the power to alter his molecular form to transform into any solid. There was a set-back, though. Once he transformed into any kind of liquid, he could not ever change back to his normal self.

List of appearances


Television and Film

  • Television series:
    • Season 2 - Attack of the Mutant Part 1 & 2

Video Games


  • Scott Wickware (television series)
  • James Belushi (video game)