Overall, very well done with this. The concept seems to be executed very well, and the attention to anatomy and motion is great.
I do think that the motion of the hair and tail could be made a bit more dynamic, since at the moment they feel a bit stiff. Also, you could possibly smooth out the transition between frames and try to emphasize the slinky/loping movement of the feline body. Cats are very springy when they move, especially when moving quickly, and I think you could do a lot to bring this into the piece. It might also be interesting if you cold add some of the springy/slinky feline feel to the human torso, adding a bit of bend to it to tie it even more to the lower body. I understand that this could be tricky with a six-limbed creature, but I think you could pull it off.
Very good. Interesting idea.