His best known roles include Oil Can Harry, Swifty and the narrator on "The New Adventures of Mighty Mouse and Heckle &amp; Jeckle", Ming the Merciless on "Flash Gordon", the Overlord on "BlackStar", Skeletor, Man-At-Arms and Mer-Man from Filmation's 1980's cartoon "He-Man and the Masters of the Universe", and the voice of Prime Evil in the 1986 TV series, Filmation's "Ghostbusters".