I think I'm with "gone" for the deer, but I'm not sure why. I think part of it for me is that the description of the parasitic creature(?) is maybe too non-descript. I know that's sort of the point, but I feel like I need some kind of visual satisfaction of this woo-element before having to accept that next piece of magical realism. Plus, I think the missing carcass might pull them further into the deep-dark-wood where something is afoot. Isn't there always in the forest after dark?

I doubt it was intended, and I can't pinpoint it, but I thought of Carlos Castaneda for a moment when reading this one. Nice job!