Looks like most of you had no trouble figuring it out--it was, in fact, the little guy you guys are calling a "bunny".
I'm sorry if anyone was annoyed by my not saying straight out what it was, but I originally wanted a few guesses just to see if I had matched the style well enough that anyone might get it wrong. Besides, he is featured quite prominently in the first screenshot, so I didn't feel like it'd be that hard. Once again, apologies to anyone who was bothered by it.
Okay, so what he's supposed to be--He's intended to be something along the lines of a shadow elemental djinn, to go along with the other four. The "bunny ears" you see were intended to be curling horns, sort of similar to ram's horns, and the front teeth were intended to look similar to the two front teeth of a stylized skull. I didn't realize how much the design ended up looking like a bunny until after i read your comments XD Kinda funny the way that happens sometimes.
Now to address what crits I actually got--adding more buffer colors in definitely on my list, so I will go ahead and add another blue betwee the lightest two. I don't know so much about lightening the darkest shade--It was intended to be a blue so dark it felt almost black, because he was intended to be a shadow elemental creature. I guess I'll try it just to see how it looks though, don't want to ignore advice out of hand, especially 'cause I do feel like the pallette needs a little work.