Or had you rather be a mule?

Bing Crosby - Would You Like To Swing On A Star.

No, mules are a hybrid between donkey and horse and are therefore sterile (they cannot produce offspring). Improved answer: Mules can mate with each other, however they can't produce offspring.

It is the offspring of a male donkey and female horse.

A horse and a donkey will happily mate, and they produce very healthy offspring: mules. However, it turns out that mules are sterile. Because of this, the horse gene pool and the donkey gene pool are...

would rather