The Mare

The Prose Edda tells how a builder offered to wall Asgard and asked the sun, the moon and Freyja as his price. Loki talked the Æsir into it on terms they thought impossible — one winter, no help but his horse — so when the work ran ahead of schedule it fell to him to break the bargain. He became a mare. The builder's stallion Svaðilfari tore his harness to follow her into the woods, the wall went unfinished, and the price was never paid. Some time later Loki returned leading a grey foal with eight legs. That foal was Sleipnir, and the sources call him the finest horse among gods and men.