Fix the anatomy!
The face: Seems longer on the far (unseen) side than on the near side, because of the eyes. The eyes on our side extend most of the way back towards the neck, but the others don't seem to. Seems the whole head doesn't line up right with the neck. The mouth/jaw doesn't center on the same line as the eyes. He has a cheekbone and jawbone on this side, but not on that side - we'd see them from this view. Are his eyes on the side of his head, or the front? The lip - he's supposed to be snarling, I think - should be drawn up, and is, but only because you cut that bit of his face out. You need to draw the lip. I'm assuming the teeth are placeholders?
The rest: It's shapeless. It's fixable, but you have to show where the hips are, and how the tail joins. Give it a consistent spine from neck to tail and work out its main muscles and where they go.
Basically, don't shade this yet. It's not done.