The unique bow, Firiniel's End does 20 points of Frost Damage and 50 points of Slow for 3 seconds but when I used it on an Ancient Dragon it caused it to crash face first from the sky and slide like 50 ft and it was struggling to get up for a few seconds. Does anyone know if there is something special about this bow or is Frost damage and the Slow effect supposed to do that?

That would be amusing to watch! LOL

I was just stunned man. Huge crash. It quaked and he slid on the ground and then slowly got back to his feet.

Dragons sometimes do that when their health is low enough and there is enough room for it, I think. Ive seen it before.

Personally, I think that should be the effect of Dragonrend. Shouting a dragon out of the sky should have been more literal.

Just like in the trailer, right? It's only happened to me a few times but it's awesome to watch. I love the land scarring too. Perhaps the dragon is poisoned and it's health is depleted while flying?

It happened several times to me. Usually when the dragon is flying and gets hit often enough by arrows will it crash-land.

This light-brownish mass ("dragon barf") can get in the way sometimes. It is layered on top of the land and it will cover items up and can make entrances impassable.