I did not find any thread on this topic, but if there is one excuse this post.
I was trying to sell TWW to a friend and showed the trailer and said: "everything you see will be in the game."
The trailer does promise that everything that is shown will be in the game right? I'd hate to be a proved a liar.
So at the very end of the trailer a Greater Pigeon of Tzeentch is shown. Is there any information (or speculation*) about what that exactly is? Is it a unit or NPC spawn that appears when the influence of Chaos is great enough?