This is a great idea. I mean, an average horse weighs what, like a ton? A dying horse should do a 1 hit kill into anything it runs against, or at least massive damage. A rider getting his horse killed out from under him should take massive ammounts of damage from the careening ton or so of flesh, muscle and bone. Of course, the poor piker and the 4 or so teamates in front of said dead horse would also get swept away, but that would only be proper :3. And since a dead horse smashing full speed into someone does so much damage, it only makes sense that a live horse trampling someone would do even more damage. You've really opened my eyes here.