Sleipnir is Odin's eight-legged horse, called the best of all horses, and his conception is one of the stranger episodes in Norse myth. The Prose Edda relates that a builder contracted to fortify Asgard in a single winter, aided by his powerful stallion Svadilfari, and came dangerously close to winning the goddess Freyja, the sun and the moon as his fee.
To prevent this, Loki turned himself into a mare, lured the stallion away, and in due course bore Sleipnir, the grey foal with eight legs, whom Loki gave to Odin. Sleipnir carries Odin between the worlds, including on the ride to Hel to seek the dead god Baldr, and his ability to travel to the land of the dead and back has led many scholars to connect the eight-legged horse with the imagery of shamanic soul-journeys, and with the old picture of a bier borne by four bearers (eight legs). He is depicted on Gotlandic picture-stones and remains the most recognisable of the mythological horses.