Iounn from the Prose Edda written by Snorri Sturluson in the 13th century, was the keeper of apples that granted Gods eternal youth. In the Skaldig poem of Haustlong, we hear the tale of how the giant Thiaza kidnaps Iounn using Loki to lure her from the Asgard, the land of the nine worlds, ruled by Odin and Frigg, of which Valhalla was one, into the woods, promising interesting apples. Once there, Thiaza in the form of an eagle, swoops down and captures her, flying away with her to his home.
The Gods then start to age, and grow old. They realise that Iounn is missing from Asgard and that Loki is responsible. He is sent to rescue her and turns into a falcon. Once at the house of Thiaza, he finds Iounn alone and transforms her into a nut, before returning to Asgard. Thiaza chases him, once again as an eagle, but the Gods are waiting and have built a pyre. As Loki nears the flames, he stops suddenly, and Thiaza shoots past him, catching his wings in the flames. As he falls to the Earth, the Gods kill him.
With Iounn safely back in Asgard, their youth returns with the apples she bestows.