Another training sprite

[Star]

Well, before adding lighting..I would suggest fixing his head because right now it looks weird.
When building a character, think of it like..an action figure toy. Think of how each part of the body would function and how it is connected to the body. Right now, it's like the head is just kinda..floating?


I simply fixed this problem by emphasizing more that it is, indeed, connected to the body.

As for lighting, try to shape the character out more. Most specifically around the horns. That way it defines its characteristics more. I'm not doing the whole thing for you because, as an artist, it is best if you do it yourself.
Another thing to note is that you need to work on your color scheme. You seem to have way too much colors going on and the colors look odd when put together(I already tried it with the highlights you made). I'd suggest working on a more stable palette. It seems to change completely different hues when put together.