Other mistake: When Captain Underpants falls in the Turbo Toilet 2000's mouth which has a liquid in it, he doesn't turn into Mr. Krupp.
Captain Underpants: The First Epic Movie (2017)
1 other mistake - chronological order
Directed by: David Soren
Starring: Kevin Hart, Jordan Peele, Kristen Schaal, Thomas Middleditch
Other mistake: When Captain Underpants falls in the Turbo Toilet 2000's mouth which has a liquid in it, he doesn't turn into Mr. Krupp.
George Beard: When I snap my fingers, you will obey our every command. You are now the greatest superhero of all time, the amazing Captain Underpants!
Mr. Krupp: Tra-La-Laaaaaaaaaaaaaaaaaa!
Answer: They never would have found him after CU slapped him far away. Plus Harold destroyed the shrink/grow machine so PP ended up permanently small, meaning someone could easily squish him if he tried anything evil again.