Guess who’s back? Captain Underpants! Author Dav Pilkey has agreed to write four more books in the 1997 series that has irked elementary school librarians and become known as “poop fiction,” reports AP. The first book, The Adventures of Ook and Gluk, Kung-Fu Cavemen from the Future, will be out in August with a worldwide printing of 1 million copies, Scholastic announced today. This is the first new Captain Underpants in four years. In an e-mail to AP,  Pilkey said he and his wife “had to take some time off to care for my father, who had terminal cancer.” His father, David M. Pilkey, died in 2008. – Ann Oldenburg