Loki in Norse mythology is the cunning, shape-shifting trickster god of mischief, fire, and chaos, known for getting the Aesir into trouble but sometimes also helping them with his cleverness, though his ultimate betrayal leading to Baldr's death results in his grim punishment—bound with venom dripping on him until Ragnarök. He's a complex figure, born a giant but accepted among the gods, with a name meaning "knot" or "tangle," reflecting his role as the fatal flaw in the gods' world.

Key Characteristics
Trickster & Shapeshifter: Master of disguise, changing sex and form, using cunning (læ) to solve problems he often created.
Ambivalent Nature: Blurs lines between good and evil, an ally and an enemy, often helping the gods out of jams (like getting Thor's hammer back) but also causing major strife.
Family: Son of the giant Farbauti, he's Odin's blood-brother and father to monstrous beings like Fenrir, Jörmungandr, and Hel.
Appearance: Described as handsome and fair ("fríðr ok fagr sýnum"), though popular imagery often gives him red hair; he's not necessarily depicted as large.
Symbols: Snakes, fire, webs, knots, and tangles, reflecting his nature.
Downfall: His trickery leads to Baldr's death, resulting in his binding until Ragnarök, when he breaks free to fight the gods.

Role in Mythology
Plot Device: A catalyst for major events, driving narratives through his schemes.
Symbol of Chaos: Represents disruptive forces, contrasting with the more stable gods, and embodies the less distinct moralities of older beliefs.
Source of Wonders: He often procures or commissions incredible items for the gods, like Thor's hammer Mjölnir.