Mules. They're sturdy, they're reliable, they're co-stars with Juan Valdez in coffee commercials. But they're sterile. Mules do not beget mules, in fact, mules do not even naturally exist in nature, because of a twisted fact that many people know: mules are what happens when a horse mates with a donkey. The mule is a genetic experiment that actually worked out to some good, unlike certain other ill-conceived hybrids like broccoflower, crystal clear Pepsi, and Christian Rock.
But the phenomenon of the mule raises one very concerning question. The fact is, that of the mule's two parents, the horse is clearly a much more attractive animal than the donkey. So just how do they get this to work? If you were a horse, would you mate with a donkey? I certainly wouldn't. What kind of unlucky horse gets that job? You could be racing in the Kentucky Derby. You could be starring in an Anheuser-Busch commercial. You could at least be getting ridden around by a cop in Canada. But no, you have to bang donkeys.
Is the horse the father? If so, do they have to get him drunk beforehand? Maybe riding a donkey is what's left after you strike out with the phillies at the horse bars. Still, I'd rather head to Taco Bell and call it a night than have to go and plow a donkey. Maybe they put a bag over the donkey's head?
Is the horse the mother? If so, what kind of self-respecting female horse allows herself to get rammed by a donkey? He better be extremely charming, or rich, or funny or something; otherwise, you just gotta feel like a real whorse (sorry) after letting that happen. Maybe she closes her eyes and imagines it's Mr. Ed?
Maybe it's artificial insemination? If so, the person with that job has an even rawer deal than the horse who has to pork a donkey. I've heard such things exist, though; perhaps if you were unfortunate enough to be in this line of work, you could at least sell your story as a sequel to the movie "The Horse Whisperer," entitled "The Horse Jerker."
I'm sure it would be Oscar material.