So I thought I'd try my hand at designing a couple of the aliens in my own way, while still maintaining the same concept and spirit of the species. I always tend towards a more cartoony aesthetic, but I think these body types could carry over well into a more realistic style. So yeah, here's a couple Vulcans and a Klingon!
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edit: oh some ideas on the designs. The Vulcans overall seem to have a higher cognitive capacity than humans, so it would seem... logical that their brains could handle a couple more limbs and eyes. Besides, more appendages = more alien. S'true. For the Klingon, I didn't stray too far from the original. Made the forehead ridges more like plating. Different head shape, feet shape. I meant to show a size comparison to humans, but think taller and wider.