Thought it was worth a bit of a whirl, this topic......
“The Mutant” and yes that is Warren Oates.
“The Galaxy Being” was the first episode broadcast.
One that springs to mind is The Zanti Misfits (S1, E10, 1963)
The models were created by Wah Chang, who was responsible for other models with unforgettable faces (self portraits?), like Balok in The Carbomite Maneuver (S1, E10 of Star Trek, 1966)
... and Land of The Lost (1974–1976)
“The Zanti Misfits” episode starred Bruce Dern.
Might be difficult, but do you recognize Martin Landau from “The Man Who Was Never Born”?
Certainly I do....but it might've been a little more difficult without the aid of prior knowledge - another of my favourite episodes for sure!
Of course having Simon Oakland play the alien lead in “Fairground Attraction” was really cool. Especially when the headpiece later made an appearance in the original series of “Star Trek”.
“Demon With A Glass Hand”
It has everything going for it:
Stars Robert Culp
Written by Harlan Ellison
Completely shot in the Bradbury Building (as seen in “Blade Runner”).
Line of dialogue, “The 20 billion people of Earth… where are they hiding?” was picked up by Cabaret Voltaire for use in their song “Yashar”.
What more could you ask for?
Agreed - 'Demon' is the best episode wadcorp, and my second fave.
I get the feeling you're a bit of a fan!