The sixth book in Dav Pilkey's mega-bestselling Captain Underpants series. Now with super-cool foil covers! Shiny! Fun! Dav Pilkey's newest epic novel finds George, Harold, and everyone's favorite superhero in their stickiest situation yet. This time, the boys' latest prank has snotty school brainiac Melvin Sneedley in a stink. And when Melvin tries to transform himself into a bionic-powered superboy, things go from bad to boogers, literally, and the Bionic Booger Boy is born!