Was Spot supposed to be a dragon? And did they ever show what he looked like, other than the fire coming out of his nose?

I remember seeing Spot's back and tail a couple of times, and yes, it did just look like you'd think a dragon would. But I don't think they ever showed a full on front view of the animal. It was kind of like the Sleestak god from Land of the Lost, or Earl the neighbor on Home Improvement, or Carleton the Doorman on Rhoda. The gimmick was that you never were supposed to really see it. :)

Just watched "A Man for Marylin" and when Spot bails up the suitor at the front fence he sounded like a dinosaur usually does in the movies.