Only Captain Underpants can stop the three evil space aliens who have invaded Jerome Horwitz Elementary School and turned everyone into lunchroom zombie nerds.
Principal Krupp once again turns into the superhero Captain Underpants in order to save the world, and Jerome Horwitz Elementary School, from the evil talking toilets and the Turbo Toilet 2000.
When George and Harold's latest prank makes a direct hit on the school brainiac Melvin Sneedly, he decides to get even.
George and Harold are always driving their teacher crazy! But this time, they've come up with much more than a prank--they've created a monster.