The "Ook and Gluk Jr." series of graphic novels is written by Dav Pilkey, who is also the author of the popular children's book series "The Adventures of Captain Underpants." Rather than attributing the books to himself, Pilkey attributes them to fictional author George Beard and fictional illustrator Harold Hutchins.
George Beard and Harold Hutchins, who are the lead characters in Pilkey's "Captain Underpants" series, decide to write the "Ook and Gluk Jr." stories after a series of disagreements with scientists. The first book in the series, "The Adventures of Ook and Gluk: Kung-Fu Cavemen from the Future," was published by Scholastic in 2010 and given an initial printing of 1 million copies. As of 2015, Pilkey is at work on a sequel to the first book.