My Gym Partner's a Monkey is an animated series created by Tim Cahill and Julie McNally-Cahill that premiered on Cartoon Network in 2005 and ran until 2008. It is based on a human boy named Adam Lyon who, through a clerical error, gets transferred to a school for animals.

Chew on This (S01E03a)

Adam, sick of the animal food in the school cafeteria, manages to get human food served, which the animals quickly get hooked on.

Leaf of Absence (S02E05b)

Principal Pixiefrog loses his job and sits around on the couch all day, eating cheese bugs and making himself fat. A mosquito gets fat by sucking Jake's blood and Jake temporarily fattens himself, by squeezing the blood back into his system

Gorilla My Dreams (S02E04a)

Windsor climbed inside of Slips' body, inflating him into his shape. He'd later jump inside of Jake, making Jake's entire body form his shape.

The Notorious Windsor Gorilla (S04E04a)

Slips eats a painting Adam made, causing his body to form a giant square shape, before digesting it.

Synch or Swim (S04E06b)

Jake's butt bomb drains all the water out of the swimming pool. Pixiefrog rushes to get a hose, so he can fill a beached dolphin student again.