A tip? .. ok Make sure that the first curved lines on top on the outside of the worm are similar in shape to its mouth on the front, you will achieve a better form/shape The shading is really simple, but it's alright so far, light comes from top right, and thus shadow is on bottom left I would make the inside of its mouth darker as no light will reach it And you could try thinner outlines, if you draw with mouse, lower the sensivity of the mouse in the settings