I used the Naga from Cataclysm's model and down-converted it with the CataToLK tool, which has never given me issues with resulting models. I checked in Blender to see if the UV's were having a good time, and everything seemed in order, and removed the hardcoded textures via 010 just in case that was causing issues, but the problem is still out in full force.
On further inspection, it seems to be that it overlays another character's face ontop of the Naga one every time another character's textures are loaded first. For example, I'll go onto an orc female in character creator and then move to naga female, and the naga female has her face but, ontop of that, a transparent, zoomed in texture from the orc female. Texture-stealing models are definitely the most confusing problem I have ever come across in modding.