"Friends and pranking partners Miles and Niles face a tough challenge when their favorite goat and nemesis, Principal Barkin, is replaced by his stern, no-nonsense father, Former Principal Barkin, who turns the school into boot camp"-- Provided by publisher.

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.

George and Harold have really done it this time--they've created a monster! She's faster, smarter, and more evil than anything the world has seen before--she's Wedgie Woman! With the help of her horrible robots and her horrendous hairdo, Wedgie Woman is on a mission to take over the world, and she'll give a whopping wedgie to anyone who stands in her way--including Captain Underpants.

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.

When the new vice principal is put in charge of Ella Mentry School for a few days, she tries out some very unusual ideas about how students learn.

George, Harold, Captain Underpants, and Sulu the bionic hamster battle the three ridiculous Robo-Boogers in an attempt to turn the Bionic Booger Boy back into Melvin Sneedly.

On the third day of school, a young boy is sent to the principal's office and thinks about all the horrifying rumors he has heard about her.

A snotty situation ensues when Melvin Sneedley, an academically-gifted student, turns into the Bionic Booger Boy and must be stopped by George, Harold, and Captain Underpants. By flipping the pages, the reader may view animated illustrations.

Rufus Leroy Williams III wants to go to school to learn to read but the principal at first refuses because Rufus is a pig.

When Professor Pippy P. Poopypants comes to Jerome Horwitz Elementary School to teach science, and he goes off the deep end because students make fun of his name, only Captain Underpants can save the school from the professor's perilous plot.