I haven’t found any special bonus yet, but that’s not to say there isn’t one, or won’t be later. Personally, I just enjoy having 8 different ravens to perch all over my house.
Edit: Just to allay confusion, that’s the six different permutations of the new ravens, the Dazed Raven Advisor, and the Bandaged Raven.
edited by Alexander Feld on 2/6/2013