The students fear getting vaccinated, resulting in Nurse Gazelle using a blowpipe to inject them. Unfortunately, she accidentally hits Adam with Jake's inoculation; he seems fine at first, but ends up regressing into a dumb ape.

A high score in the school placement test puts Adam in the honors class where he is teased by the students at first, but he is soon respected by them when they see his excellent spelling skills.

Coach Gills teams Adam and Jake as one player for the Charles Darwin middle school football team when Adam displays excellent memory at the game play and Jake displays his good arm for tossing.

After Adam and Jake break a fish tube, Jake's consequence is to work in the school office filing papers, while Adam's punishment is to guide an endangered panda, Dingbang, around the school.

After Adam complains about the cafeteria food, Principal Pixiefrog replaces the animal food with human food which causes the animals to get fat from the unhealthy human foods that are supplied.

Jake is offended after Adam complains that Bull Sharkowski "went ape" on him, so Adam tries to make up to Jake, though Jake keeps refusing the apologies.

When Adam accidentally hits resident Bull Sharkowski's snout, he is dubbed as the new school bully.

Mrs. Chameleon thinks that Jake should have the role of Jungle Guy but Adam wants the role also.

Slips is shedding his old skin but everyone thinks it is a virus he is spreading around the school called the AAACCCK.

When Jake finds a diamond doorknob, he discovers its power when all of his classmates (except Adam) become enchanted with the item due to its shining, causing Jake's obsession of his butt to go to far, making all of the students study only monkey butts.

Ignoring warnings from his pals, Adam befriends a sad little koala named Deidre. Soon,

Charles Darwin Middle School becomes condemned because of bat guano.

Jake fills in for Principal Pixiefrog after he loses his voice.

Ingrid's new friend tries to steal Ingrid's life; Mr. Hornbill has an annoying new pet, so the gang plan to get rid of it.

Adam meets Jake's parents and spends a day playing monkey in their habitat at the zoo.

Bull Sharkowski finally gets his braces off and, due to his extreme vanity,

Adam learns that Jake is nearly blind and convinces him to get glasses.

Jake is inspired by a guest speaker to become a mountain goat.