(written from a Production point of view)
Robert Phillips (10 April 1925 – 5 November 2018; age 93) was an actor who portrayed the illusory space officer seen in the Star Trek: The Original Series episode "The Cage" and later, via re-used footage, in the first season episode "The Menagerie, Part II". He filmed his scenes for "The Cage" on Friday 4 December 1964 at Desilu Culver Stage 15. He received no credit for his appearances.
Phillips was a former policeman turned actor and also appeared in the film Hour of the Gun (1967, with Steve Ihnat, William Windom, William Schallert, Monte Markham, and Dave Perna and music by Jerry Goldsmith) and in the television movie Mitchell (1975, with Jerry Hardin).
Phillips died on 5 November 2018. (Screen Actors Guild Magazine, Special Edition 2019, p. 96)