Requires a lot of imagination or some props to show that these guys are horses and a Martian.
Cast: 2 Horses, Martian, perhaps some costumes
Setting: Race Track
If necessary, explain that these are two horses and a Martian.
#1: You know, I had a bad day on the track today. My rider must have eaten a lot last night, because he was a lot heavier than usual, so my back got really tired and I almost tripped.
#2: I've had similar problems. My rider hits me in the side so much with his feet that I can't run because it hurts so much.
#1: Say, did you hear that the ugly mare is going to be entered into the grooming contest? The mane on that thing just doesn't compare to either of ours.
#2: You're right. Things in the racing world just don't seem to be fair to us horses.
Martian: You know, I could help you two out with your problems.
#1 & 2: Look! A talking Martian!