I think the last one is the best. I personally prefer vector graphics for a clean, crisp look (the current look is in some half-way land between pixely retro and non-pixely... If it's supposed to be retro I'd suggest making it more pixely). Also, I'm wondering if a less detailed horse might look better (given the black and white theme).
Also, does Kosh mean "night"? (and what language?) Just curious.