Who wrote the shark boy and lava girl book?

dumb answer: a guy named Kris lol ur so dumb 4 not knowin that alreedy

smart answer: The dumb answer was just a joke, don't take it to heart. It was actually a series of books by Chris Roberson. Book one, which might be the one you have, is The Day Dreamer, and book 2 is Return to Planet Drool. A third one was announced, but has yet to appear, called Deep Sleep. If you're a fan of the book series, I recommend getting the second and waiting for the third.