In Futurepast's dream sequence, who do you all think is wearing the black sequined Carrousel costume? The actor is uncredited at the end of the episode. I have a suspicion that it actually may be Donald Moffat - our very own Rem. They way this actor talks makes me believe that it's Donald doing the part.

REM? Is that you?
Steve, that's an interesting observation. I think you might be correct.
Steve,
I think you may be on to something there. I hadn't noticed it before, but you're right - the Black Costumed character is uncredited in the end credits. It may indeed be Donald in that outfit. It does kinda sound like him, too.
Since each episode was a bit expensive to film, it would make sense for them to use a regular salaried cast member for the 'mysterious' role instead of hiring another actor off the street and paying them full SAG wages.