American children's novel by Dav Pilkey (credited as "George Beard and Harold Hutchins"), categorized as part of the author's Captain Underpants series of books as a spin-off to the series.[1] It was published on February 5, 2002. It tells the story about an African-American baby named Billy, who got superpowers after childbirth and came along with his talking pet dog named Danger Dog, who partnered with Deputy Dangerous. Thus, they became superheroes as Diaper Baby and Diaper Dog, while Deputy Dangerous transformed into a poop and took over the world.