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.

Dog Man, a crimefighter with the head of a police dog and the body of a policeman, faces off against his archnemesis Petey the cat. Dog Man, the newest hero from the creator of Captain Underpants, is still learning a few tricks of the trade. If only the Chief would throw him a bone every once and a while ... Dog Man needs to dry up the drool, dust away the dander, and roll out of the refuse if he's going to impress the Chief, and he needs to do it...

Dog Man, the newest hero from the creator of Captain Underpants, is still learning a few tricks of the trade. If only the Chief would throw him a bone every once and a while ... Dog Man needs to dry up the drool, dust away the dander, and roll out of the refuse if he's going to impress the Chief, and he needs to do it fast! Petey the cat is out of the bag, and his criminal curiosity is taking the city by storm. Can the canine crime biter unleash justice...

"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.

Only Captain Underpants can stop the three evil space aliens who have invaded Jerome Horwitz Elementary School and turned everyone into lunchroom zombie nerds.

"Flippy, Molly, Li'l Petey, and twenty-one baby frogs each have something to say. Naomi and Melvin don't see eye to eye and Poppy perceives the world differently than her siblings. Will the baby frogs figure out how to work together and appreciate one another's point of view -- both inside and outside the classroom?"--

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, 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.