Super Diaper Baby is a 2002 graphic children's novel by Dav Pilkey that is a spin-off of the Captain Underpants books. The book follows Billy, a baby who gains superpowers after birth. Billy teams up with a super-powered Jack Russell Terrier, Diaper Dog, to fight the latter's former master, a sentient piece of feces named Deputy Dangerous.
A sequel was published in 2012.