That expression is wicked cool. The framing is really nice, but there is one little distracting bit in the lower left-hand corner. You might crop from the bottom just a hair to remove part of it and minimize its impact. Also, you could use curves and selectively lighten up the half of the hyena's face that was in shade.
I've attached an example of what could be done just by masking part of the face and opening up a Curves dialog for that section. I set a new gray balance (again, it only affects the masked part of the image) and bumped the curve upwards just a touch. Just something to consider.
Thanks for the comments guys:). David thanks for PS instruction, certainly makes a difference. Alfred, believe me those are milk teeth, the adults have an unbelievable set of dentures!:D