The Adventures of Captain Underpants: Color Edition by Dav Pilkey

Fourth graders George Beard and Harold Hutchins invent the wedgie-powered superhero Captain Underpants in the first book in this #1 New York Times bestselling series by Dav Pilkey, the author and illustrator of Dog Man!

George and Harold are a couple of class clowns. The only thing they enjoy more than playing practical jokes is creating their own comic books. And together they've created the greatest superhero in the history of their elementary school: Captain Underpants! His true identity is SO secret, even HE doesn't know who he is!