That would be Mick Jagger, who went for an offer of a secondary role in a TV pilot. "He did a lot of ad-libbing. Some of the funniest stuff in the pilot came from him." says Rob Burnett, one of the writers of the show, which is called "Let's Rob Mick Jagger."
I like seeing Mick Jagger get recognition for his comic acting. Remember when he played the role of Keith Richards in an SNL sketch with Mike Myers (who played the part of Jagger) in a "Point/Counterpoint"? And there was another SNL sketch where Jagger and Jimmy Fallon both played Mick Jagger, as Mick Jagger looking in a mirror.