Horses can be very brave/stupid and protective of their herd. Many dogs have lost their lives to horses (or Moose), and snakes live dangerously around horses. Back in the days, a brave stallion would also take on a bear that would get too close to his herd.
This is the first time I've seen them take on an Alligator though.
Nice capture!
"Bring a compass. It's awkward when you have to eat a friend."