Uh Oh Dynamo (S1E13)
A monster called the Fish Balloon Monster sucks a large amount of air, inflating himself into a gigantic size before attacking Townsville. The Powerpuff Girls uses a robotic vehicle called the Dynamo to fight the monster, destroying more parts of the city in the process. The girls then pop the monster by throwing three sharp gears shaped like ninja stars at his mouth, sending him flying into a giant statue resembling Mount Rushmore.
Ironically, the balloon monster is immune to flames and explosions despite being easily popped by sharp objects.
Beat Your Greens (S02E04a)
All the kids of Townsville battle alien vegetables by eating them. One boy gets too full after eating so many of them.
Imaginary Fiend (S02E09a)
Candy is Dandy (S03E08a)
The Mayor ends up bloated as well as the girls after eating the candy he shared with them as a reward.
Musclebound Monster (Cartoon Network Block Party #46, 2008)
Professor Utonium realizes that he needs to exercise when he finds out he has grown a potbelly.