Through a mix-up at the Central School District's Admissions Office, Adam Lyon is accidentally transferred to the all-animal Charles Darwin Middle School, where all the zoo animals send their kids. Fortunately, on his first day of school, Adam meets Jake Spider Monkey and the two become fast friends. However, Adam quickly realizes that having a monkey for a best buddy isn't always easy. With signs that warn "Do Not Eat the Other Students," Adam will have his hands full making it through middle school alive.
After losing the part of Tarzan in the school play to Jake Adam challenges his best buddy to a “Tarzan-off” to see who really would make the best King of the Jungle, but things get out of control fast and both end up out of the play.
Adam is made the school football team’s quarterback because he can remember the plays; unfortunately he has no athletic ability and must work with Jake, the former quarterback, to try and earn the school their first win ever.
When Adam is accidentally inoculated with MONKEY BOOSTER, he “goes ape,” turning into a crazed, pants-less monkey! It’s up to Jake and the faculty to hunt down MONKEY ADAM and bring him back to his senses before he drives everyone bananas!
Adam and Jake have to sell candy for the annual school fundraiser. Unfortunately, the candy they’re selling is CHOCOLATE COVERED GRUBS, and nobody’s buying.
It’s Howl-o-ween at CDMS and Adam will do just about anything to get away from the incessant howling – including going down to the depths of the school’s scary boiler room to retrieve a file for Principal Pixiefrog.
Adam’s offhanded complaint about the lack of “human food” in the cafeteria causes a lawsuit-fearing Principal Pixiefrog to replace ALL of the school’s usual foodstuffs (grubs, oats, slop) with pizza, corndogs, hamburgers and other things humans eat.
After discovering a stash of Mr. Hornbill’s unsent love letters to Mrs. Tusk, Adam and Jake agree to coach the painfully shy Mr. H in developing techniques to woo the cafeteria lady of his dreams.
When his human friends and animal friends both accidentally get invited to his birthday bash at the local pizza palace, Adam has to find ways to keep the two groups apart or risk embarrassing himself in front of his old school’s BMOC.
An innocent lie about being allergic to animals backfires, causing Adam to walk around inside a plastic bubble. But instead of Adam being ridiculed, bubbles become the latest fad at school – and soon, everyone is wearing them!
After boy cheerleader Dickie Sugarjumper is injured, the very reluctant Adam is recruited by the Charles Darwin Jungle Squad to cheer with them at the extreme cheerleading finals.
Adam goes back to his old school during an exchange program, and realizes things aren’t exactly as he remembers them. Jake joins him, and has trouble distinguishing Adam from the other humans.
When Jake hears Henry Armadillo sing, he quickly enters him into the school talent show and books him a TV gig, without realizing how terrible he is. Will Adam be able to stop them before Henry makes a fool of himself on national television?
Principal Pixiefrog’s worst nightmare comes true when he’s successfully sued for the first time in his career. He takes some time off to “get my tiny head together” but ends up going to pot.
In a school assignment designed to teach responsibility, Adam, Jake and the gang are given eggs to care for. But when the eggs hatch, Adam realizes fatherhood is more than it’s cracked up to be!
Jake decides to take a day off from school. But in typical Jake fashion his day off from school is going to be spent at school – enjoying all the facility has to offer without those annoying classes getting in the way.
The carnival comes to CDMS and while Jake and his animal buddies enjoy everything it has to offer, Adam becomes totally obsessed with winning a cheesy “Princess Ballerina Snow Globe”.
Upon receiving his report card, Adam discovers that, rather than letter grades, CDMS gives out generic positive symbols like smiley faces and rainbows.
Jake thinks Adam is trying to usurp his title as CDMS’ resident “Prank Master General.” Soon, Adam is unwittingly embroiled in a prank war that he wants no part of.
It’s spring at CDMS and that can only mean one thing, time to impress all the other kids with your sense of fashion. But this year the competition for top fashionista gets so out of control that Pixiefrog institutes a school uniform policy.
After Adam borrows a pencil from Phinneas Porpoise, he finds himself indebted to the Spiffies. To pay back the debt, Adam agrees to make a secret “delivery,” but Jake tags along, and things quickly go south.
Adam spearheads the United Species, an animal version of the United Nations. Upset that his pal is spending more time with the United Species than with him, Jake determines to bring the organization down.
Confused by gorilla mating rules, Windsor runs scared from a female gorilla named Deb, fearful that if he even speaks to her, he’ll be forced to marry her one day, since gorillas mate for life.
Slips oversleeps during class and gets trapped in night school. Adam, jake and the gang come to the rescue to save Slips from certain doom at the hands of the creepy night denizens of CDMS.
Pixiefrog’s irrational fear of being kissed turns out to be not so irrational after all, when, after a smooch from Warthog, he turns into a tiny human prince.
Adam insults Rufus Hyena, causing the chronic laugher to become a chronic cryer. Rufus’ sorrow drives everyone crazy, and it’s up to Adam to make Rufus laugh again.
In the hope of scoring a leather jacket for Jake, Adam joins The Ferals, an after school “club,” full of tough cats, and is put through a hair-raising initiation.
Due to another clerical error, Jake Spidermonkey finds out he’s actually Jake Spiderplant, and is transferred to Creeping Broad-Leaf Sedge Middle School, where he has a hard time fitting in with his fellow plants.
After pulling two straight weeks of all nighters before final exams, Adam goes feral. Jake is overjoyed, hoping to finally realize his dream of training a wild child for the National Wild Boy Competition.
Adam discover the only reason he’s never been eaten or seriously maimed at CDMS, is because of his “special” status. Adam demands the status be removed, and when it is, he finds out the true meaning of “survival of the fittest.”
Jake’s wish to live in a real live musical comes true, after he knocks the wish granting “David Coppertrout” out of the Central Stream. Soon, everyone is singing, all the time, except ironically, for Jake.
