The Encyclopedia of Indo-European Culture theorizes that Sleipnir's eight legs may be the remnants of horse-associated divine twins found in Indo-European cultures and ultimately stemming from Proto-Indo-European religion . The encyclopedia states that "[...] Sleipnir is born with an extra set of legs, thus representing an original pair of horses. Like Freyr and Njörðr , Sleipnir is responsible for carrying the dead to the otherworld." The encyclopedia cites parallels between the birth of Sleipnir and myths originally pointing to a Celtic goddess who gave birth to the Divine horse twins. These elements include a demand for a goddess by an unwanted suitor (the hrimthurs demanding the goddess Freyja ) and the seduction of builders.