Interesting use of strong shadows. If you're going to use strong shadows, though, you probably want more fine detail lines (I'm looking at the parts of his chestfur that stick out and the hilights on his toes on his right foot here).

I don't draw flying critters that much with armwings because it's hard for me to figure out where the 'wing' part should go in certain poses. It seems you've got that down pretty well, though. :)

I really like the stark contrast in the shading here. Nice job. It really gets the mood across well. :D