I think you should spend a lot more time on the basics of this. Don't just run in with the line tool, then the paint bucket and slightly dither parts. Take more time and create a solid base concentrating on volumes and forms depending on this creature. It looks very off-balance and - even though its not a real creature - anatomically couln't exist.
It's good that your starting small, but a few basic art skills / physical studies would benefit you more before pixel shading techniques.