Beautifully done, the background is gorgeous. Only, if you don't mind, even though I myself suck at action-y pictures, I have a few pointers.

Both of their gazes seem to be a bit off. The girl defending isn't so bad, but she seems to be looking just a tad too far up. The attacking one's gaze seems to be looking straight ahead, but should be directly on the girl that she is attacking (lower down).

Another thing, to make them seem like they are more 'life like' in their movements, both girls should be leaning to the right a bit more.

Also, the shiny-ness of the fox's tail seems a bit much in comparison to the lighting of the rest of the picture, especially because the raccoon seems to have absolutely NO shine on her tail OR hair (I understand she's more in the shade, but at least a little shine should be used so that she more matches the other character).

But otherwise, I really respect your willingness to try action pictures (and that GORGEOUS background) I seem to have a lot of trouble with them and it takes a lot of talent and practice to get them right. Keep doing them! I'm excited to see more of these. Most people don't have the balls to try them.