Walter Burke

 played The Great Zeno in the first season episode, It's Magic (1965).

Career
Walter Burke was a prolific performer of stage, film and television. He began his career in the 1920s, performing on Broadway in musicals and dramas. In 1948, he made his film debut in "The Naked City", followed by "All the Kings Men" (1949). He went on to appear in twenty more films such as "Dark City" (1950), "Never Love a Stranger" (1958), "Jack the Giant Killer" (1962), "My Fair Lady" (1964), "The President's Analyst" (1967) and "The Stone Killer" (1973). His television credits included "The Twilight Zone", "Perry Mason", "The Untouchables", "Bonanza", "Lost in Space" and "The Lucy Show". Closing out his career in the early 1970s, he moved to Pennsylvania and became an acting teacher.

Source
McNeil, Kenneth and Griffith, John "J-Cat". Walter Burke on findagrave.com, August 24, 2002. Retrieved on February 13, 2020.