On the design, i like it, but the inner outline color doesn't work, not even at 2x zoom. I'd darken it considerably (between 10-20% lightnesst).
Regarding the animation, i see you've worked on it a lot and made it quite smooth, but i think that punch would be quite uneffective. It only reaches slightly beyond the creature's head, he would have to be really close to the foe to do any damage, and that's unrealistic. He'd have a much better use for the tail or legs, which have much greater reach. To have an effective punch, make the shoulder move way forward with the arm (while the other shoulder moves simmetrically way back, and have the waist rotate significantly), or even make his right hip move forward too, moving the whole upper body forward increasing the range. Otherwise, it's a pretty useless (or symbolical) jab.
Also, the tail seems to pop into place, at the last frame. Make it slide back into place.
On the other creatures and icons, they're great! The Pokemon inspiration is quite obvious though, but that's not bad.
Edit: Also, the toes on the foot are moving in the wrong direction. They should move back instead of forward, since he's putting his weight on the ball of the foot so the heel moves forward, and the toes appear to move back.
