I can't take credit for this as I found it out there on the internet. I was amused, so I thought I'd share.
In the animal world when a donkey is mated with a mule the result is a jackass. The modern term now for a jackass is a schumer. Unlike a mule, noted to be a dependable hard working animal, in contrast, the schumer is exceedingly belligerent, un-dependable, and spends much of it's time braying at the world. Braying is somewhat of a disgusting sound emitted by a schumer, often at the same time peering out at whomever is in it's area. Schumers are often found just standing around in the barnyard, braying, and more than likely will be waiting for a hand-out of hay rather than heading out to pasture to forage for its self. Schumers are essentially worthless as a working animal on a farm.