The Big Superhero Wish - S4-E3
Continuity mistake: I don't remember if it's this episode or not... When Timmy opens his locker and finds a stack of papers, and they fall on him, they multiply to fill the whole hallway.
The Big Superhero Wish - S4-E3
Continuity mistake: Probably around the time when Elmer (kid with boil) the normal kid bends the Baby Shredder (Vicky's) claws, the boil jumps from one cheek to the other, and Elmer's making it do that.