In thinking about the variations between cowponies and how the coat patterning and horn shape and position are determined by race, I realized that there’s nothing in place for lesser used pony races like batponies, changelings, sirens and donkeys.  If anyone’s interested in a cowponed variation of any of the listed species feel free to suggest attributes to help differentiate them from those already seen, i.e. unicorn, pegasi, earth pony and alicorn.