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.

A skateboarding principal offers unusual incentives to his students to motivate them to learn more.

Tired of following the strict rules of their grumpy replacement principal, second-grader A.J. and his classmates try to find a way to bring back eccentric but lovable Principal Klutz, who was fired for bringing a wild turkey to the school's Thanksgiving Day assembly.

"Prepare for plenty of giggles as a kindergarten class arrives for their first day of school, but can't find their teacher--only a delicious-looking sandwich and the words 'Mr. S' scribbled on the chalkboard. Chaos ensues as the kids argue whether or not the sandwich must be their teacher"--