Are you trying to emulate a retro felling by making it pose like nes mario? If not, there a lot to improve on his pose which you could make much more natural with amount of pixels you have at that scale.
If the stiff posture with bent legs is intentional for a retro look (it might as well be the case), then the first thing I would do would be change the shirt color to have more contrast with the pants, the same goes for the shoes.
Still about the shirt, perhaps change it to something less default than just a shirt while you are at it. Is he a grunt? How would he dress like if his kind existed as a species and a culture? Primitive and barbaric? Futuristic-Barbaric (space-grunt/starwars gamorrean)?
Think of an atire that fits and give a shot making the different parts with sufficiently contrasting colors, and we will surely give you input on how it comes out.
Lastly, try to redraw the head more rounded at the top, avoid perfect diagonals, and try to remake the same features (under fang sticking out, dark eyes, big nose and ears, without using single black pixels. Make the head a little larger if you need more space to show all that, it won't hurt it. Give it a try, let's see where you get with him