Sweet giraffe! I like it
The main problem I see with these is there's a little too much going on in your 16x16 pixels. In the walking animation, I'm not sure what the grey thing is. I think it's a shield? It'd probably look better without it.
As far as the walking animation, I think it looks like he's going backwards because in the last frame, the front leg shouldn't touch the ground. Try removing one pixel off the front leg and you should notice a difference.
On the overhead sword attack: Great! I think it's too slow though. Try speeding up the animation, and it's just fine
The uppercut looks strange, but uppercutting with a sword is strange anyway. I'd recommend replacing it with a stab. This would read better and probably be easier to animate anyway.
Those are my only critiques. Really cool giraffe, and good job on squeezing so much detail into such a tiny space. I can barely stand to do 24x24, much less 16x16.
