Dean Gerard Winters (born July 20, 1964) is an American actor. He is known for his role as Ryan O'Reily on the HBO prison drama Oz and has also appeared on such television series as Rescue Me, 30 Rock, and Law & Order: Special Victims Unit, as well as portraying "Mayhem" in a series of Allstate Insurance commercials. He co-starred in one season of the CBS Network cop drama series Battle Creek and currently has a recurring role as the Vulture on the comedy series Brooklyn Nine-Nine.