"Poison Ivy" is a short story in More Tales to Give You Goosebumps.
Matt, the main character of this story, is sent to sleepaway camp by his parents. The name of the camp is Camp Wilbur. Even though Matt doesn't want to go to camp, he still has to spend four weeks at Camp Wilbur. Matt is assigned to a cabin with four bunkmates. Vinny, Mike, and Brad. Vinny and Mike are fine, but Brad is hard to deal with. Brad brings three trunks with him and wears stinky aftershave. Shortly after meeting his bunkmates, Matt decides to leave and join a softball game. A boy named David tells Matt that he can play in left field, and another camper tells Matt to look out for poison ivy.
Later that night, Matt is awoken by a scratching sound. Matt leaves his cabin in search of the noise's source. The closer he gets to the baseball field, the louder the noise gets. While Matt is busy guessing where the sound is coming from, he stumbles across a patch of poison ivy. The poison ivy is alive! The small patch of ivy is writhing around. Matt runs back to his cabin to warn his bunkmates. None of his friends believe his story.
The next morning, the baseball field is overrun by poison ivy. All the kids assume that the new plants can't be poison ivy because they grew so fast. Everyone plays around in the piles of ivy, and they all end up getting rashes. Two of the camp counselors, armed with weed whackers, try to get rid of the ivy. Both counselors disappear. Later that night, Matt and his bunkmates are awoken by scratching. Poison ivy covered their cabin while they were asleep. The boys in Matt's cabin have to fight off the ivy to prevent it from entering their cabin. They discover that the poison ivy hates the smell of Brad's aftershave. The plants retreat whenever they are close to it.
The boys decide to spray the aftershave everywhere. The living plants recoil and slither away. After the plants are gone, everyone at Camp Wilbur begins to cheer for Matt and his friends. Their celebrations are cut short when they see something that looks like a tornado. Brad's aftershave attracted a giant swarm of mosquitoes.