Sleipnir

Sleipnir was the horse of the Norse King Sitric Silkbeard of Dublin in 1006. He was named after the eight-legged horse of the same name from Norse mythology. King Sitric rode Sleipnir on a three journey from Dublin to the Abbey of Kells to retrieve the Book of Kells. The King was very fond of his horse and often spoke to him as if he were a person. (BFA: The Book of Kells)