He is still incomplete, thanks to Umbakarna for making 4 simple animations for him. At the moment he is just a NPC, not an enemy and his run looks a tad ridiculous, but thanks to newer versions of Amnesia 1.3 or 1.31 supporting Blender animations and Umbakarna's work on fixing the vertices around the Panthers mouth he can now be animated without any issues or used as a NPC.
Umbakarna's message to developers:
I say it is incomplete because so far the entity has only 4 basic animations and I made it into NPC entity (not enemy)
Perhaps someone can use it in this form already, or improve what I started, I send this early before finishing because I have no idea when will I have more time to work on the rest of animations.
Of course the animated version is only compatible with 1.3 and 1.3.1 updated Amnesia because only those support Blender animations.
And that was probably the reason why there was problem rigging the entity before. Either because original creator tried to animate it in Blender and in that time the support was quite limited to the animations... And there were also bad vertices around the mouth area, I had to fix them, otherwise the result animation would be screwed up. I admit that the RUN animation is kind of ridiculous and other ones are not really best quality but at least I tried. I am currently working on modding quite hard and there is barely any time for side work recently.