For most horses, 4 ears are common and due to a mutation in some foals, 2 ears can be found. This results in a lower range of hearing. Most of these horses are in domesticated herds as they have more protection.
An unusual overgrowth of keratin that often results in horns or plates to grow on normal skin. Due to its hardened nature, it often acts as an armour or weapon to the horses that have it. If on an undesirable place it will need to be routinely shaved by the owner of the horse, in the wild though herd members will help out the afflicted horse.
A mutation that effects the eyes. Horses affected by this are seen with a more brilliant color of eyes. Only the homozygous version of this mutation will glow, but all will have an altered look. For brown eyed horses they carry a more gold coloring and for blue eyed horses it is more akin to a frigid ice.