I'd do a mutant but mutants are just humans with genetic variance not normally found in the gene pool. That aside; Elves, Dwarves, Orcs, and other humanoid Tolkien species are fair game for me. Hell, I'd do more animal-like species too like Mermaids and Centaurs. The really hard part, for me anyway, would be doing something non-humanoid like a Dragon but that would really, really be case sensitive to me. If it's like Fire Emblem where Dragons have a humanoid form, sure but other dragons.. coin toss it.
/tangent
Pixel Art can be fun.