The rabbit's closer foot seems to fade into the mushroom since is has no defining line like the rest of him.

If you are going for a no line (albeit it doesn't seem that way for this particular one), then I would suggest on the foot in particular really adding shading between the toes and the colouration on the feet so it can be distinguised from the mushroom a bit better. I would say that the foot could exist like that if the lighting was right, but since the rest of the drawing is all nicely segregated, somewhat stylized and line dependent then it would be best to change it.

I do like this piece a lot though, the bright colours and the reds go nicely I think c:

Side note; the proportions of the anatomy pieces a couple of posts up are a bit awry.