Odin’s eight-legged steed
Odin’s mount, a grey steed with eight legs, the swiftest horse of the nine worlds, able to gallop through sky, earth, and the underworld alike. Its origin is strange: to delay a giant building a wall, Loki took the shape of a mare and lured away the giant’s stallion, and afterward bore this eight-legged steed and gave it to Odin. On Sleipnir, Odin ranges the nine worlds, questions the dead, and even rode all the way into the underworld to plead for his beloved son Baldr.
After Baldr’s death, Odin’s son Hermóðr borrowed Sleipnir to go to Hel’s underworld and plead. The eight-legged steed galloped nine nights along the gloomy road of the dead and leapt clear over the high wall of the underworld. Without this steed that could pass between the realms of the living and the dead, the gods would have had no chance even to ask death for Baldr’s return — it is the living bridge joining the nine worlds.
Below are how modern works borrow or reinterpret this name or story — not the original material. The two differ, so keep them apart.