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.
Kristína Horková Book order (chronological)
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 are having a normal kind of week. Yesterday they found out they were going to flunk fourth grade. Today they've created an evil, super-powerful monster. She's mean. She's got a fake-fur Evil Baddie costume - and she's having a really bad hair day. With the help of her robots, the Wicked 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. Watch out.