Are You A Horse?

For young cowboys and little scientists, an ARE YOU MY MOTHER? for the 21st century!

For his birthday, Roy's freinds give him a saddle and some very specific instructions:
1. Find a horse.
2. Enjoy the ride!

But there's a problem; Roy doesn't know what a horse IS! So he sets off to find out with hilarious results: A snake tells him to look for a creature with legs. A crab has six legs, but he's too unfriendly to be a horse. A chameleon smiles at Roy, but horses don't change color... What's a horseless cowboy to do?