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.

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.

The Bad Guys are about to have a very bad day! Mr. Wolf and his bad buddies have messed with the wrong guinea pig--one who is secretly an evil mad scientist. And, the nasty little furball wants revenge! Will they survive? Will they be heroes? And will they ever stop trying to eat each other? It's time for the Bad Guys to spring into action!

The Bad Guys have strangely acquired SUPERPOWERS! But their powers might be, well, defective. They can only do things like blow their own pants off in public. Not exactly what you'd call hero-caliber skills. Defective or not, the Bad Guys have a job to do. With Marmalade ready to destroy the world, Mr. Wolf, Mr. Snake, Mr. Piranha, and Mr. Shark finally have their chance to be (super)heroes! And this time, they may just get some help ...

In the aftermath of a war between gods and men, a hero, a librarian, and a girl must battle the fantastical elements of a mysterious city stripped of its name.

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.

Victor and Eli started out as college roommates-- brilliant, arrogant, lonely boys who recognized the same sharpness and ambition in each other. In their senior year, a shared research interest in adrenaline, near-death experiences, and seemingly supernatural events reveals an intriguing possibility: that under the right conditions, someone could develop extraordinary abilities. But when their thesis moves from the academic to the experimental, things...

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.

Transgender demigod Teo is unexpectedly selected for the Sunbearer Trials, a fierce competition among demigod heroes where the winner sacrifices the loser to Sol, their blood fueling the Sun Stones that protect Reino del Sol.

Infuriated by the declaration that Pluto is no longer a planet, President Penguin and his penguins invade Earth and it is up to Ricky and his robot pal to defeat them--with some help from Ricky's cousin Lucy and her pets.