Keene Curtis
From Smurfs Wiki - Smurfology
Keene Curtis (February 15, 1923 – October 13, 2002) was an American character actor. Born in Salt Lake City, Utah, Curtis made his film debut in the 1948 Orson Welles adaptation of Macbeth. Additional film credits included American Hot Wax, Rabbit Test, I.Q., and Heaven Can Wait. He was responsible for the voice of Lord Balthazar in the Smurfs cartoon show.