When George and Harold hypnotize their principal into thinking that he is the superhero Captain Underpants, he leads them to the lair of the nefarious Dr. Diaper, where they must defeat his evil robot henchmen.

"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." -- P. [4] of cover.

When a principal loves his school so much that he wants the children to attend classes every day of the year, it's up to his students to show him free time is a good thing, too.

When Mr. Lincoln, "the coolest principal in the whole world," discovers that Eugene, the school bully, knows a lot about birds, he uses this interest to help Eugene overcome his intolerance.

Only Captain Underpants can stop the three evil space aliens who have invaded Jerome Horwitz Elementary School and turned everyone into lunchroom zombie nerds. Includes CD with songs by Koji Matsumoto and other features.

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.

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.

Mr. Klutz is retiring! (A surprise even to him, courtesy of scheming Dr. Carbles.) Vice principal Mrs. Jafee thinks it's her time to shine, but Dr. Carbles has hired someone else for the job! Stand-up comedian Mrs. Stoker is ready to defend her place as principal in a joke-off against Mrs. Jafee. Will Mrs. Stoker have the last laugh? Or will she lose her audience when things get serious? 

Cuando el profesor Pippy P. Poopypants llega a la escuela primaria Jerome Horwitz para ense?ar ciencia, y se vuelve loco porque los estudiantes se burlan de su nombre, solo el Capit?n Calzoncillos puede salvar a la escuela de la peligrosa trama del profesor. 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...