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.

A small mouse named Ricky Ricotta and his best friend, a giant flying robot, save the world from Victor Von Vulture and his vicious voodoo vultures from Venus.

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.

A small mouse and his best friend, a giant flying robot, attempt to save the Earth when an evil Martian monkey and his mechanical creations attack. Includes brief Flip-o-Rama section that simulates animation and instructions for drawing six characters.

George and Harold's attempts to hypnotize their teacher results in the creation of the monstrous Wedgie Woman who sets out to rule the world by getting rid of Captain Underpants.

Two incorrigible fourth graders named George and Harold create a superhero named Super Diaper Baby and write a comic book about his adventures.

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.

After being sent to jail for the rest of their lives, George and Harold are taken on a trip back in time by Tippy Tinkletrousers back to their Kindergarten days where they must deal with their bully without the help of Captain Underpants.