 He started writing for television, with a 1993 and a 1994 episode of "Rugrats", then regularly working on "Beavis and Butt-head" between 1994 and 1997, when he joined "The Simpsons" as a writer and producer for seasons nine through twelve (1997–2001).Other television writing credits include one episode for "Daria" and two episodes for "Liquid Television".After the widespread critical success of "The Simpsons", Doyle went on to write several episodes of "CatDog", considered among the finest examples of contemporary television.