I'm extremely disappointed that I haven't seen this yet as I was sold this game on the pretence that dragons picked up mammoths. I even witnessed some dragon on mammoth action the other day but, alas, there was no swooping and picking up of the mammoth. In fact, the mammoth somehow managed to kill the dragon.
I did see an ancient dragon come swooping at me today though but I nailed him with an arrow so he crash landed instead leaving a pretty cool furrow in the ground.
It is funny when they crash land. I might've seen a dragon grab someone as they flew past once (one of the Guards in the first dragon fight) but otherwise I've never seen them pick up anyone. They fail so badly against Giants and Mammoths. Hell the earlier versions lose fights against Frost Trolls, Giants/Mammoths wipe the floor with them.
Got hold of the Dragonbane sword, definitely gonna have to enchant a bow with that.