Thanks :) his back is meant to be super-short, that's just what he is [as I said in the OP]
This is the finished image, I flat coloured and lined Luce [left off his prism markings because I'm lazy and the setting is dark, and prism markings don't show up much if at all in the dark] and the other person shaded and did the lovely Artemis [the liver red dun roan mare, with blue markings] who is her character and the design belongs to her. Species design is mine. Arti is Luce's mate btw :)
the dA upload
I'm on deviantart as 2close2dasun.