At bedtime, Principal Fred's wife, son, and dog help him search for his missing teddy bear so that he can go to sleep.

Frustrating his sister with his tendency to transform into a monkey whenever he gets hyper, Clyde is given an extra-firm reason to try to control his energetic behavior when a new school principal moves into the neighborhood.

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

It's a new school year with the same old problems: the school is going to run out of money! A local engineering competition might just keep them funded for another year. Can Millie and her friends Pearl and Halinka invent a way out of the mess? With some guidance from their eccentric headmistress Miss Bunsen, anything seems possible.

Por burlarse del nombre del profesor Pipicaca, Jorge y Beto están a punto de hacer que su nuevo maestro de ciencia enloquecido de rabia se apodere del planeta entero. Pero Capitán Calzoncillos viene al rescate. 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...

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.

Contains three stories in which brothers and best friends Wilbur and Orville Riot catch a thief, overthrow a king, and find a treasure, and includes rules to some of their made-up games.

A modern take on "Mary Had a Little Lamb" featuring hilarious antics as Lizard sneaks into Mary's backpack and causes nothing but mayhem in her Kindergarten class. He eats someone's lunch, makes a mess in the painting corner, and scares the teacher silly during story time before being sent to the principal's office to wait for Mary's mom to pick him up. It's no fun being alone. But when Mary finally comes home from school, Lizard knows he'll always...

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.

George and Harold hypnotize their principal who, believing he is the superhero Captain Underpants, leads them to the lair of the nefarious Dr. Diaper. They must then defeat his evil robot henchmen.