Unicorns
Unicorns are said to be the source of magic, weavers of spells. Their horns store magic inside, and using it to heal others takes a toll on the user to an extent - The horns can't bring back the life of another without the life of the user dying in turn. Some unicorns have tuffs of long fur around their hooves, some have longer tails shaped similar to a lion. But all have the long, crystalline horns.