George and Harold, and their doubles, Yesterday George and Yesterday Harold, have a good thing going. Two of them go to school, while the other two hide in the tree house and play video games all day-then they switch! But when their malicious gym teacher, Mr Meaner, creates a method of mind control that turns their fellow students into attentive, obedient, perfect children, the future of all humanity will be in their hands!

"George and Harold thought their porcelain problems were behind them, but the Turbo Toilet 2000 is striking back! The carnivorous commode known for devouring everything in its path has built up a real appetite... for REVENGE! Luckily, the fate of humanity is once again in the hands of George and Harold and their annoying nemesis Melvin Sneedly. Will Wedgie Power prevail? Or will the amazing Captain Underpants be flushed away forever?"--

"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.

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.

George and Harold's time-traveling Purple Potty has landed them in a crazy place! The teachers are nice, the cafeteria serves delicious food, and the school principal, Mr. Krupp, thinks they're hilarious. Something is very, very wrong -- and it gets even worse when the boys' pet pterodactyl, Crackers, and Sulu the Bionic Hamster are captured by George and Harold's evil-twin look-alikes. Now George and Harold must face their greatest foes yet: THEMSELVES!...

Captain Underpants's spookiest--and stretchiest--adventure yet! George Beard and Harold Hutchins are back in a new Halloween adventure! Piqua's biggest pranksters are getting ready for the best holiday ever--Halloween, of course. But their dreams of costumes, candy, and haunted houses go down the drain when Mr. Krupp and Melvin start a campaign to make Halloween illegal! That's when George and Harold come up with HACK-A-WEEN, a totally legal spin-off...

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 to their Kindergarten days where they must deal with their bully without the help of Captain Underpants.

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 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...

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