The herd of mountain kelpies have black coats and silver manes and tails obviously they don't hunt the normal kelpie way (drowning humans in nearby lochs or seas). Instead they hunt larger prey like eagles and small dragons. They are far bigger than any other equine.
The introduction of Solaramen and Lunarathen. At this point they are about 6 and are leaving their home town after their parents were killed by a kelpie. The rest of the village see them as cursed so they are forced to make a living elsewhere.