Arnold Moss also played "Kodus the Executioner" in the original Star Trek series episode "The Conscience of the King". One of the better one's -- dealing with madness, murder and betrayal.

I've never had a chance to see any "Man from U.N.C.L.E." episodes. That's interesting to know.

Some of Moss' more entertaining performances on RMT (I think) include:

The Fall of the House of Usher
The Canterville Ghost
The Damned Thing
A Pair of Green Eyes
Ocean of Emptiness (Mainly for his writing--he really only has a
Cameo)
The Long,Long Sleep (Entirely for his writing)
The Ice Palace
And, of course, this episode which he wrote.