Awww what a cliffhanger.
Chekov's gun (for the gauntlets) would say that whatever it is would turn out to be an enemy, but maybe it will turn out to be an ally? However, for some reason I doubt it. I think they were partially sent there to get killed and also facilitate the birth of whatever it is.
I feel like the art around the eye more resembles feathers than scales, but it could just be a drawing style. Maybe it's a cockatrice, phoenix, roc, or thunderbird? Could be dragon related as well. It's really tough to guess from what we've glimpsed, though. Hell, they may even go with some sort of chimera beast like a manticore/nue/hippogryph. Guess we'll have to wait.