Loki
Loki is the son of the giant Fárbauti, and thus in terms of paternal lineage he is not one of the Æsir: Snorri implies as much when he says describes Loki as ‘also counted among the Æsir’ (Gylfaginning, 33). Loki is the archetypal trickster figure found throughout world mythology: ‘one whom some call Slanderer of the Gods, the Source of Deceit, and the Disgrace of All Gods and Men… Loki is pleasing, even beautiful to look at, but his nature is evil and he is undependable’ (Gylfaginning, 33). Later, Loki and his offspring fight against the Æsir at Ragnarök.
Whilst an ally of the Æsir, however, Loki is willing to sacrifice his own honour to save them, though his slippery nature is manifest in all such incidents. For example, a giant smith once offered to build a wall around Asgard to keep the giants out, but demanded Freyja and the moon and sun as payment. The gods agree, but only if he can do so in one winter. To avoid paying him the agreed price, Loki turns himself into a mare, and distracts the builder’s mighty horse long enough to delay construction. He gives birth to an 8-legged foal.
Loki’s equine son, Sleipnir (‘fast-traveller’), is given to Odin as a gift, but Loki has other unequivocally monstrous children who fight the gods at Ragnarök. By the giantess Angrboda, he has the wolf Fenrir (who bites off Tyr’s hand, and kills Odin at Ragnarök), the Midgard Serpent (slayer of Thor at Ragnarök), and Hel, a half-blue woman who rules over the dead unwanted by Odin and Freyja at the roots of Yggdrasil. As in Sleipnir’s conception, Loki’s untrustworthy character is demonstrated here: he can produce animal offspring, and is willing to sleep with giants, the sworn-enemies of the Æsir.
Ragnarök aside (see final item), Loki’s worst crime is the death of Baldr. Baldr is the wise and handsome second son of Odin, who takes an oath from all things that they will not kill him. Much sport is had by the Æsir in pelting Baldr with things that cannot kill him. Loki is furious about this, and disguises himself as a woman to ask Frigg (who helped Baldr obtain the oaths) whether anything can harm Odin’s son. She reveals that mistletoe was deemed too inconsequential to consult. Loki thus smears a spear with mistletoe, and seeks out Baldr.
Loki hands the spear to Baldr’s blind brother, Hödd, who innocently throws the spear at Baldr, killing him instantly. Baldr is the first Æsir to die: ‘this misfortune was the worst that been worked against the gods and men’ (Gylfaginning, 49). Attempts to revive Baldr fail, Loki’s treachery is discovered, and he is caught by Thor trying to escape justice in the form of a salmon, and chained to a rock for eternity. It is unclear why Loki is not simply killed as punishment, and sparing his life turns out to be a fatal mistake from the Æsir.