Kelpie

Kelpie - horse from the books about the witcher by Andrzej Sapkowski. Beautiful mare with perfectly black hair and a mane of the same color. Quick, nimble, and attached to her owner. Could be summoned with a magic bracelet.
She was named after a sea monster: kelpie.

"Vysogota knew little about horses and their breeds, but he was an esthete, he knew how to recognize and appreciate beauty. And the black horse, shining like anthracite, which he saw on the background of the birch trunks, was strangely beautiful. She was the essence of beauty. She was so beautiful that she seemed unreal."

"The mare thumped the ground with its front hooves, whinnied, stood sideways, as if asking to be admired. Ciri could not suppress a sigh of delight at the sight of this neck, straight and slender, but strongly muscled, a small, shapely head with a convex forehead, high at withers, and a physique that delights with proportionality."
~ The tower of the swallow
*self-translation