This is a very interesting photo, it really pulled me in when I first looked at it. The subject has a very interesting look that captures your attention. Although I think that the composition is tight for this shot and that you should have tried to get it a bit wider. Specifically I'd like to see the ends of the ears and horns rather than them cut off at the edges.

I also think that it is a bit dark and perhaps a contrast adjustment would do the photo some good and increase the impact. I do love the look on their face though, I would be rather freaked out if they gave me such a look. The sharpness of the face is also very good, although maybe a hair more depth of field would be interesting. All in all I do like the shot although with some of those small changes you can really make it great.