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.

Harold and George's time-traveling Purple Potty lands them in an alternate universe where everything seems delightful, but evil lurks just beneath the surface, and leads to a battle between Captain Underpants and his own evil twin.

"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.

The monstrous Turbo Toilet 2000 is determined to take revenge on George, Harold, and Captain Underpants.

Anne Shirley has left Redmond College behind to begin a new job and a new chapter of her life away from Green Gables. Now she faces a new challenge: the Pringles. They're known as the royal family of Summerside - and they quickly let Anne know she is not the person they had wanted as principal of Summerside High School. But as she settles into the cozy tower room at Windy Poplars, Anne finds she has great allies in the widows Aunt Kate and Aunt Chatty...

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.

"George and Harold are behind bars for a crime they didn't commit! But just as they are settling into their new life, they are pulled from prison by a time-traveling tyrant named Tippy Tinkletrousers! Now the boys are taking a trip back in time to the carefree days of kindergarten, when the scariest thing they had to face was not evil mad scientists or alien cafeteria ladies but a sixth-grade bully named Kipper Krupp, the nephew of their clueless...

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.

Matilda, a brilliant, sensitive little girl, uses her talents and ingenuity to seek revenge on her crooked father, lazy mother, and the terrifying Miss Trunchbull, her wicked headmistress, and save her beloved teacher, Miss Honey.

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.