Very cool! Love the fur shading and the pose. Thought it looked familiar despite not having heard of a bies but I see it can also refer to a chort. I can see I'm going to learn a lot of interesting stuff from this collab and it'll be a lot of fun with pieces this good in it.
I think some point bies and chort became intertwined with each other, or maybe even a local name for the same demon. Thanks for the comment.