Mad-Shagger
A person who can't stop humping anything that moves, even if it's not human or slightly attractive.
My uncle is a mad-shagger. He once tried to have sex with a goat. It didn't work. He got kicked.
My friend's dog is a mad-shagger. It chases every mailman, firefighter, and pizza delivery guy.
My teacher said I'm a mad-shagger. I was making out with the principal's cat during lunch.