In the project, McKean (Hairspray, The Homecoming) and Begley Jr. (November at the Mark Taper Forum, "St. Elsewhere") will be joined by Fred Willard ("Anchorman"), Don Lake ("Return to Me") and Chris O'Dowd ("Bridesmaids").
The project centers on Tom Chadwick (O'Dowd), a 30-year-old who recently lost his job and his girlfriend. He begins to explore his family heritage after inheriting a mysterious box from a great aunt he never met and uncovers a world of unusual stories and characters.
McKean will play Tom's father, Keith, with Begley as his Uncle Andy. Willard will play Andy's neighbor, and Lake will be a friend of Tom's cousin.
HBO ordered eight episodes of the single-camera half-hour comedy.
