A vastly underappreciated writer-performer, Martin Mull enjoyed sporadic success in mainstream entertainment, but comedy fans knew him as a sly and erudite wit whose middle-of-the-road appearance belied an irreverent and often biting sense of humor. Despite his “low” profile (at least by modern Hollywood standards), Mull enjoyed a 30-year-plus career as an actor, stand-up comic, writer, producer, voice-over artist, and most recently, a celebrated artist....