I'm having mixed feelings.
Pure black? It's attracting ALL the attention. But it's very cool like that. There's a nice effect, because my eyes are drawn to it like a black hole, I have to consciously pull away to look at the rest. But if this wasn't intentional... XD XD
If you want it to read like a normal piece, try lightening the black?
aside from the contrast, it's pretty clear what they are. Maybe heavier line weight on castor's fur right below his mouth, the one pixel lines are too sharp for the somewhat cushy cushy soft ^0^ style.
?