Dav Pilkey 's first book in the phenomenally successful Captain Underpants illustrated chapter book series, perfectly suited for reluctant readers and especially boys.George and Harold are best friends. Much to the dismay of Mr. Krupp, the principal of Jerome Horowitz Elementary School, everything includes circulating their Captain Underpants comic books and playing practical jokes. The boys manage to hypnotize Mr. Krupp and make him think he's Captain Underpants. He rushes off to fight crime. After some amazing adventures, Mr. Krupp hits his head and becomes Mr. Krupp again.Dav Pilkey is the author of 'Las Aventuras Del Capitan Calzoncillos / The Adventures of Captain Underpants (El Capitan Calzoncillos / Captain Underpants) (Spanish Edition)' with ISBN 9788434870475 and ISBN 8434870479.