jow good are you with adapting patterns?
I was thinking of the Connemara Pony:
http://www.knittingdaily.com/media/p/35977.aspx
Use that, make the head more square, work in the spots in the color choice you make, maybe tilt the head down further,
add horns if you like, do not do the mane and tail this way, but no mane and a solid "bone" tais with a tuft on the bottom, just braided, maybe?