great stuff !
a coupple of suggestions for the anim: The motion of the tail looks a bit too fast. The first few frames are fine, but i seems to speed up in the end. Add a few frames and slow the last part down. A bit of tail action after he finishes his punch would look cool anyway. Also, you might wanna contrast the arm/torso abit, otherwise the animation might end up a bit too cluttered.
Anyhow, great job, looking forward to the colored vers. of the anim!