TryNinja is right. It is possible to use only the avatar in APNG format. I don't have a chance to test it right now. Perhaps theymos was off already and the APNG format.
Has anyone tested if this works? I still see animated avatars for campaigns.
I was editing some pictures in PS a few days ago when I realized it have a feature for making gifs. I tried making a rather crude animated version of my avatar, only to find I can't upload it.