Richard and Ted become suspicious of the creepy new principal at Crosswell Elementary School when students who get sent to his office return with very changed, strangely submissive attitudes.
A new school year presents the Freaky Joe Club with its greatest challenge, saving their school's nickname from a new principal with a mysterious aversion to hamsters.
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.
When George and Harold use their traveling purple potty to travel to another dimension where the school is nice and the principal, Mr. Krupp, thinks they're funny, they meet up with their evil twins and must face their cleverest enemies ever -- themselves.
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.
Only Captain Underpants can stop the three evil space aliens who have invaded Jerome Horwitz Elementary School and turned everyone into lunchroom zombie nerds.
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.
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.
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.
