I have two horses out of my 5 that do the predator stomp. I also have a donkey that is real good at the torture the silly young predator gig. He will kick, bite and stomp if he has too but prefers scaring the pants off them and running them into the electric fence. I've seen him do it a few times now and there is no doubt the donk is laughing when the predator goes screaming back into the woods.
I like those types of horses. We have problems with the neighbor's feral pigs, and I watched our Icelandic Horse go Animal Kingdom when one tried to get into his pasture. He went into a rage and FLEW at them. He also keeps the other neighbor's goats out. Love those ornery horses!
Although it's less fun when the same horses *also* stomp your pets to death. I used to know a horse that killed at least 6 barn cats during the year or so I was acquainted with him. It was really gruesome.
One of my mares beat the tar out the neighbor's lab once. If you ever wondered if a horse can user her teeth and pick up a 60 pound dog by its hindquarters and throw it 15 feet, yes it can. BTW the dog lived, but never attempted to chase my horses again.