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.

"The Supa Buddies have been working hard to help Dog Man overcome his bad habits. But when his obsessions turn to fears, Dog Man finds himself the target of an all-new supervillain! Meanwhile, Petey the Cat has been released from jail and starts a new life with Li'l Petey. But when Petey's own father arrives, Petey must face his past to understand the difference between being good and doing good."--Publisher.

Turned into a human and banished from Olympus, Apollo must restore five ancient oracles to reclaim his godly powers. Apollo (aka Lester Papadopoulos) is now at Camp Jupiter in the San Francisco Bay Area, where the Roman demigods are preparing for a desperate last stand against the evil Triumvirate of Roman emperors. Hazel, Reyna, Frank, Tyson, Ella are among those who will need Apollo's aid to survive the onslaught. It may be time for him to call...

Will is forced to overcome his fear of Wargals, the foot soldiers of rebel warlord Morgarath, as Araluen's army prepares to battle Morgarath's forces.

"OK. A lot of the stuff we said on the back of the last book was NOT TRUE. We now admit that The Bad Guys is WEIRD. We also admit that it features ALL the weird stuff we said it didn't. PLUS there's now a whole bunch of even weirder stuff involving an over-sharing bat, a really scary new character who lives in the woods, and a strangely confident little guy with a mullet. So, uh, don't relax, maybe FREAK OUT a little and have your MIND BLOWN by the...

As Hava sails across the sea toward Monsea with the world's only copies of the formulas for the zilfium weapon, she makes an unexpected discovery about one of the ship's crew, but before she can unravel the mystery, storms drive their ship off course, wrecking them in the ice far north of the Royal Continent.

Now a full-fledged Ranger, Will must rescue his friend Alyss from a rogue knight and uncover vital information needed to ward off a Scotti invasion.

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.

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.

Still yearning to be seen as heroes, Wolf, Shark, Snake, and Piranha set out to rescue ten thousand chickens from a high-tech cage farm--but one unexpected problem is Mr. Snake himself, also known as "The Chicken Swallower."