While not a “monster”, I suppose, Sleipnir is definitely what we’d call a “legendary creature” around here;his parentage is quite interesting. His father was Svaðilfari — a stallion that had “dealings” with the god Loki who was at the time in the form of a mare.
Long story short, a stonemason (who so far has been unnamed) offered to build a fortification for the gods that would keep out invaders in exchange for the goddess Freyja, the sun, and the moon. He claimed he could complete it in three seasons.
The gods agreed, after some debate, but put many restrictions on the builder, including that he had to complete the work with the help of no man. Only one request was made from the builder–could he use his horse, Svaðilfari to haul the stones?Through the influence of the god Loki, this was allowed.
Utilizing his almost supernaturally strong stallion, the builder began to complete the fortification well ahead of schedule, and the gods realized that they may have had to live up to their deal with the him. They held Loki responsible for this mess, and proclaimed that he deserved a horrible death if he couldn’t figure out a scheme to make the builder forfeit his (well-deserved) payment.
So one night, Loki disguised himself in the form of a mare–in heat, to boot–and pranced out in front of the builder and Svaðilfari. Svaðilfari broke his tack and made a dash for the mare, who led the frantically amorous stallion on a wild goose chase through the woods all night. The builder lost all momentum with building the fortification, and Loki ended up birthing an amazing eight-legged grey foal somehow, sometime later.
In addition, it was discovered that the unnamed builder was a hrimthurs, in disguise,and he was later killed by Thor with his hammer.
Sleipnir, having eight legs and tremendous speed, was described as “the best horse among gods and men.” He is mentioned in the writings Prose Edda, Hervarar saga ok Heiðreks, and Völsunga saga, and the horse in Gesta Danorum is generally considered to be Sleipnir.
There are also picture stones from the island of Gotland, Sweden, that date from the 8th century and depict eight-legged horses: the Tjängvide image stone and the Ardre VIII image stone. Most scholars believe the images depict Sleipnir. On each stone a rider(generally considered to be Odin) can be seen sitting atop an eight-legged horse.
There is a poem in Hervarar saga ok Heiðreks— Heiðreks gátur, that has a riddle mentioning Odin on Sleipnir:
- Gestumblindi said:
- “Who are the twain
- that on ten feet run?
- three eyes they have,
- but only one tail.
- Alright guess now
- this riddle, Heithrek!”
- Heithrek said:
- “Good is thy riddle, Gestumblindi,
- and guessed it is:
- that is Odin riding on Sleipnir.