Peter Hannan created the American animated television series CatDog for Nickelodeon. The show follows the lives of two identical brothers, one of whom is a cat and the other a dog. The series was created by Nickelodeon in Burbank, California. The first episode aired on April 4, 1998, before the show's formal debut in October of that year. The episode "Fetch" was also released in theaters alongside The Rugrats Movie. A made-for-TV film named CatDog: The Great Parent Mystery was released near the end of the series' run. Reruns aired on Nicktoons until 2011, then on TeenNick as part of the The '90s Are All That block. Nickelodeon Animation Studio and Peter Hannan Productions produced the series, which was published on DVD.