By Dav Pilkey, Author & Illustrator. George and Harold are up to their old tricks again, and when their latest prank makes a direct hit on school brainiac Melvin, he decides to get even! But in the blink of an eye -- and the sneeze of a nose -- the Bionic Booger Boy is born! Can Captain Underpants clean up this catastrophe, or will the mucous monster make a mess of things? For ages 7 and up.