He is an hysterically funny character on "Curb Your Enthusiasm" named Leon Black (coincidentally, Howard named his cat after the Leon Black who called Howard the "Leonardo da Vinci of radio"). JB Smoove and Larry David are so funny together they could be the whole show.
This. I didn't really like it until Season 6 when he started coming in.
Black guy from Curb Your Enthusiasm. Here he is "whiting" it up for Cosmo Kramer:
JB is pretty funny, but I know I saw that episode and I can't remember this scene. That's how bad "Curb" is vs its first 3-4 seasons. It's all made-up shit, but the last several seasons SEEM made up and random. The early ones were funny because it was real shit.