I can't seem to find these. I thought they were a type of shot glass. No luck online.
My friend, who is trying to find these glasses, said they were in "The Godfather" movie in the restaurant scene. I don't have the movie, so I don't know what they look like.
A pony is a small shot....as in a "pony of brandy"...less than a shot. Commonly stemmed but doesn't have to be. A pony holds an ounce a shot an ounce and a half.