Parker (The Ambassadors of Death)

Private Parker was a UNIT soldier who served under Brigadier Alistair Gordon Lethbridge-Stewart. He guarded Space Control's fuel bay and demanded Reegan's pass before being knocked out and his unconscious form hidden. (TV: The Ambassadors of Death)

Behind the scenes
Parker's name is never given in on-screen dialogue; his name is only given in the closing credits. He is also left unnamed in the novelisation.