Mull was nominated for a Primetime Emmy Award for Outstanding Guest Actor in a Comedy Series for a four-episode appearance he made on HBO’s political satire Veep in 2016.
Born in Chicago to an actress and a carpenter, Mull began his show business career as a songwriter and became known as a musical comedian. He opened for Frank Zappa and Bruce Springsteen at numerous live gigs in the early 1970s.
He also studied painting and graduated in 1965 from the Rhode Island School of Design with a Bachelor of Fine Arts.
In a 2013 interview with the A.V. Club, he said of his acting career that “every painter I know has a day job. They’re either teaching art at some college or driving a cab”.
“I just happened to luck into a day job that’s extraordinary and a lot of fun and buys a lot of paint,” he said.
As well as his daughter, Maggie, a TV writer, he leaves his wife, Wendy Haas, an actor and composer whom he wed in 1982.