very nice, suits the blizzard art style quite well. i like that you made a simple, yet effective big image that translated to a great 64x64 result. i give it a 4/5
if i were to nitpick, your nose could be drawn better (i still see dark lines on the nostrils - remember no dark lines to define shapes!) and if you'd compare it to reference pics its shading doesn't make much sense. however, in the final icon it's not visible enough to be a huge deal.