Best known for being a child actor on the television series Diff'rent Strokes, on which Gary Coleman's character would regularly ask him, "What'chu talkin' 'bout, Willis?"
He decided to become an actor at age 6 after watching an episode of Sanford and Son.
He grew up in San Francisco and was on the TV show Roots before later playing the role of Monk on Everybody Hates Chris.
He married Dori Bridges in 1998, and the couple had a son that same year. He has has a daughter named Bo.
He once worked with Chris Rock on the TV show Everybody Hates Chris.