It was hard to choose which one to critique. This one was personally my favorite. The idea to put it on a leaf was magnificent. It brings out the idea of nature, if that was your idea, and if not, it simply matches. I personally like the shading. It makes the catipillar look more relalistic with a '<img src="e.deviantart.com/emoticons/w/w…" width="15" height="15" alt="" title="Wink/Razz" />udgy and circular' form.
The morphing colors you did with the dark blue against lighter shades, and then your dark green against light green makes the colors look more realitic, instead of having basic colors that don't do images as must justice.