I like how you're leading the viewer with your shapes. You could add a bit more marginal since now the composition is a little tight.
A light source that is coming directly from the left gives easily a flat feeling. Might be more interesting to have the light coming from an angle. Also, try using warm/cool color contrast when shading. That means warm colors for highlights and cool colors for shadows. Or you can do it the other way around too.
The claws could be darker since now they create lots of contrast.