"The son of giants, Loki was the fire god, but also a mischievous trickster and shape-changer who grew bored with the repetitive life of the gods. Many of his exploits caused great damage or hurt, but he was usually quick enough to restore order and prevent complete disaster. In one case, he caused the gods to temporarily lose the source of their immortality. In another situation, he tricked Thor into a threatening situation for his own gain, but later devised the clever plan to recover Thor’s stolen hammer.
His tricks became increasingly nasty and evil, peaking when he caused the death of Odin’s son Baldr. When he tormented and insulted the gods at a great banquet, the gods turned on him and he escaped temporarily by changing into a salmon. He could not escape Odin’s all-seeing vision, however, and Loki was bound up in a dark cave. Loki’s first marriage to a giant produced three fearsome and evil creatures: Fenrir the wolf, the great serpent Jormungand, and Hel, the partially decomposed goddess of the underworld. He had two sons, Vali and Narvi, by a second marriage. At the time of Loki’s imprisonment, Vali was changed into a wolf that killed Narvi. The dead man’s intestines were used to bind Loki in the cave beneath the mouth of a giant snake, dripping venom, where he waited for Ragnarok. Loki was destined to lead the army of evil at that final battle with the gods, where he would be killed by Heimdall."