Idun

Norse Mythology: Goddess who is married to Bragi and is the keeper of the apples which keep the gods eternally young. The storm giant Tjasse abducts her and the gods start to age until Loki kills the giant and retrieves Idun. Goddess of youth, her name means "The Rejuvenating One".

(Nicole Cherry, A list of Norse Beings, http://www.ugcs.caltech.edu/~cherryne)