Alan Oppenheimer

Alan Louis Oppenheimer (born April 23, 1930) is an American actor and voice actor. He has performed numerous roles on live-action television since the 1960s, and has had an active career doing voice work in cartoons since the 1970s. He was well-known of doing the voice of a character He-Man and the Masters of the Universe known as the main antagonist Skeletor, later he was doing the voice as Papyrus in the 2019 computer-animated film UNDERTALE.