In Norse mythology, Sleipnir (Old Norse: ; "slippy" or "the slipper") is an eight-legged horse ridden by Odin. Sleipnir is attested in the Poetic Edda, compiled in the 13th century from earlier traditional sources, and the Prose Edda, written in the 13th century by Snorri Sturluson. In both sources, Sleipnir is Odin's steed, is the child of Loki and Svaðilfari, is described as the best of all horses, and is sometimes ridden to the location of Hel. The Prose Edda contains extended information regarding the circumstances of Sleipnir's birth, and details that he is grey in color. Sleipnir is also mentioned in a riddle found in the 13th century legendary saga Hervarar saga ok Heiðreks, in the 13th-century legendary saga Völsunga saga as the ancestor of the horse Grani, and book I of Gesta Danorum, written in the 12th century by Saxo Grammaticus, contains an episode considered by many scholars to involve Sleipnir. Sleipnir is generally accepted as depicted on two 8th century Gotlandic image stones: the Tjängvide image stone and the Ardre VIII image stone. Scholarly theories have been proposed regarding Sleipnir's potential connection to shamanic practices among the Norse pagans. In modern times, Sleipnir appears in Icelandic folklore as the creator of Ásbyrgi, in works of art, literature, software, and in the names of ships. Attestations Poetic Edda In the Poetic Edda, Sleipnir appears or is mentioned in the poems Grímnismál, Sigrdrífumál, Baldrs draumar, and Hyndluljóð. In Grímnismál, Grimnir (Odin in disguise and not yet having revealed his identity) tells the boy Agnar in verse that Sleipnir is the best of horses ("Odin is the best of the Æsir, Sleipnir of horses"). In Sigrdrífumál, the valkyrie Sigrdrífa tells the hero Sigurðr that runes should be cut "on Sleipnir's teeth and on the sledge's strap-bands." In Baldrs draumar, after the Æsir convene about the god Baldr's bad dreams, Odin places a saddle on Sleipnir and the two proceed to the location of Hel. The Völuspá hin skamma section of Hyndluljóð says that Loki produced "the wolf" with Angrboða, produced Sleipnir with Svaðilfari, and thirdly "one monster that was thought the most baleful, who was descended from Býleistr's brother." Prose Edda In the Prose Edda book Gylfaginning, Sleipnir is first mentioned in chapter 15 where the enthroned figure of High says that every day the Æsir ride across the bridge Bifröst, and provides a list of the Æsir's horses. The