From Wikipedia, the free encyclopedia. Harold Joseph Lennix III (born November 16, 1964) is an American actor. He is known for his roles as Terrence "Dresser" Williams in the Robert Townsend film The Five Heartbeats (1991) and as Boyd Langton in the science-fiction series Dollhouse. Lennix co-starred as Harold Cooper, assistant director of the FBI Counterterrorism Division, on the NBC drama The Blacklist. Lennix also played J'onn J'onzz/Calvin Swanwick/Martian Manhunter in the DC Extended Unive...