(written from a Production point of view)
Stewart Moss (27 November 1937 – 13 September 2017; age 79) was an American character actor who made two appearances on I AM ERROR first as Starfleet lieutenant junior grade Joe Tormolen (sciences division) in the episode "The Naked Time". His next role was as the Kelvan Hanar in "By Any Other Name". Moss was a friend of casting director Joseph D'Agosta, who originally considered him for the role of Dave Bailey in "The Corbomite Maneuver". (These Are the Voyages: TOS Season One)
Moss filmed his scenes for "The Naked Time" between Thursday 30 June 1966 and Monday 5 July 1966 at Desilu Stage 9 and Stage 10. He filmed his scenes for "By Any Other Name" between Friday 10 November 1967 and Wednesday 15 November 1967 at Stage 9 and Stage 10.
Moss made several appearances on the television sitcom Hogan's Heroes from 1965 through 1968 (and one more in 1971), primarily playing the recurring character of Olsen. He made guest appearances on many other TV series, including Perry Mason (1964, 1966), the "Man in a Chariot" episode of The Fugitive (1964, with Peter Duryea, Edward Madden and Gene Lyons), the two-part "Ride the Wind" episode of Bonanza (1966, with DeForest Kelley), Mannix (1968), The Invaders (1968, with Lincoln Demyan, Peter Mark Richman, and Susan Oliver), Hawaii Five-O (1969), Barnaby Jones (1976, 1978, with Lee Meriwether), Archie Bunker's Place (1980, with Jason Wingreen and Bill Quinn), Quincy, M.E. (1981, with Robert Ito and Garry Walberg), T.J. Hooker (1985, with William Shatner, Martin Cassidy, Eric Server, Gwen Van Dam, Richard Herd, and James Darren), and Matlock (1986, with Jonathan Frakes, Betty McGuire, Gary Werntz, and Julie Cobb).
He also appeared in the TV movies Sarge (1971, with Ricardo Montalban and David Huddleston), Guilty or Innocent: The Sam Sheppard Murder Case (1975, with George Murdock, Shelby Leverington, Gene Dynarski, Paul Kent, Jerry Hardin, Paul Lambert, John Crawford, Paul Fix, Claudette Nevins, and William Windom), and The Last Hurrah (1977, with John Anderson, Robert Brown, Leslie Ackerman, Mariette Hartley, James B. Sikking, Bill Quinn, Arthur Batanides, and Harry Basch. In 1974, he appeared as Kenneth O'Donnell, Special Assistant to President John F. Kennedy, in TV's The Missiles of October. Co-starring in this movie were Harris Yulin, Kenneth Tobey, Nehemiah Persoff, Peter Canon, Paul Lambert, Keene Curtis, and Byron Morrow.
His feature film credits include the John Wayne war drama In Harm's Way (1965, with "By Any Other Name" co-star Barbara Bouchet and Star Trek composer Jerry Goldsmith playing a pianist), Fuzz (1972, with Steve Ihnat, Peter Brocco, Jack Perkins, Vince Howard, and Bert Remsen), Zigzag (1970, with William Marshall, Robert Sampson, Vic Perrin, and Steve Ihnat), and Raise the Titanic (1980, with Michael Pataki, Mark L. Taylor, and Michael Ensign). He also worked with his wife, Marianne McAndrew, and fellow TOS guest stars Paul Carr and Michael Pataki, on the 1974 horror movie The Bat People.