Iðunn is a Norse goddess associated with apples and youth. She is also described as the wife of the skaldic god Bragi, and in the Prose Edda, also as a keeper of apples and granter of eternal youthfulness.

Iðunn is described as Bragi's wife and keeper of an eski (a wooden box made of ash wood and often used for carrying personal possessions) within which she keeps apples. The apples are bitten into by the gods when they begin to grow old and they then become young again, which is described as occurring up until Ragnarök. Gangleri states that it seems to him that the gods depend greatly upon Iðunn's good faith and care.

There is a tale that describes Iðunn being abducted by the jötunn Þjazi. Pjazi, in the form of an eagle, noticed that Loki is stuck to him and struggling to be free when he was thrown by Bragi in the form of a pebble. Loki shouts and begs the eagle for a truce, and the eagle responds that Loki would not be free unless he made a solemn vow to have Iðunn come outside of Asgard with her apples.

Loki accepts Þjazi's conditions and returns to his friends Odin and Hœnir. At the time Þjazi and Loki agreed on, Loki lures Iðunn out of Asgard into "a certain forest", telling her that he had discovered some apples that she would find worth keeping, and told Iðunn that she ought to bring her own apples with her so that she may compare them with the apples he has discovered. Þjazi arrives in eagle shape, snatches Iðunn, flies away with her and takes her to his home.

As a result of her absence. the Aesir begin to grow grey and old at the disappearance of Iðunn. After realizing that Loki is to blame for her disappearance, the gods threaten Loki with death and torture. Terrified, Loki says that if the goddess Freya will lend him her "falcon shape" he will search for Iðunn in the land of Jötunheimr. Freya lends the falcon shape to Loki, and with it he flies north to Jötunheimr. One day later, Loki arrives at Þjazi's home. There he finds that Þjazi is out at sea in a boat, and that Iðunn is home alone. Loki turns her into a nut, holds her in his claws, and flies away with her as fast as possible.

Loki successfully returns the goddess back to Asgard, but Pjazi was already on his tail in his eagle form. However, before Pjazi was about to reclaim his prize, Loki in the form of a falcon flies over the fortification of Asgard and and drops down by the wall. The eagle, however, misses the falcon and is unable to stop. His feathers catch fire and the eagle falls within the gates of Asgard. The Aesir kill the jötunn Þjazi "and this killing is greatly renowned."