Sleipnir (pronounced "SLAYP-neer") is the eight-legged horse son of Loki and the horse Svadilfari. Hence, he is also the half-brother of Hel, Jormungand, Fenris Wolf, Alex Fierro and Samirah al-Abbas.
Odin uses the steed as his mount, so only he can summon Sleipnir as a result.
Magnus Chase and the Gods of Asgard
The Sword of Summer
Sleipnir is mentioned when Hearthstone summons one of his children to help him and his friends get to Geirrod's castle.
Trivia
- Rudolph the Red-Nosed Reindeer, the most famous of all Santa’s helpers from a Christmas story of the same name, was inspired by Sleipnir.
- Rudolph and his red nose was actually inspired by Sleipnir's habit of feasting on the entrails of Odin's enemies.
- Sleipnir could be considered as the Norse counterpart of Arion.
- Both are horses.
- Both were born to a god/goddess who were disguised as a horse (Loki and Ceres).
- Both are very fast horses, way faster then every normal vehicle.