Elli

In Norse mythology, Elli (Old Norse "old age") is a woman who is the personification of old age, but still maintains her strength.

Myths and Legends
In the book Gylfaginning, Þórr and his companions Loki and Þjálfi are in the hall of giants where they meet difficult challenges testing their strength and skill. Þórr has just been humiliated in a drinking challenge and wants to get even. Challenging the master of the hall, a giant named Útgarða-Loki, to a wrestling match, the giant instead has him fight an old wizened woman first. According to the book, the fight went as follows:

"There is no need to make a long matter of it: that struggle went in such wise that the harder Thor strove in gripping, the faster she stood; then the old woman attempted a hold, and then Thor became totty on his feet, and their tuggings were very hard. Yet it was not long before Thor fell to his knee, on one foot. Then Útgarda-Loki went up and bade them cease the wrestling, saying that Thor should not need to challenge more men of his body-guard to wrestling."

Later, when Þórr and his company are safely out of the hall the giant explains that Þórr's opponent was much more formidable than she appeared to be and that Þórr's prowess was, in fact, astonishing.

Old Age and the Norse Gods
Elli is not mentioned in any other source but the notion that not even the gods are immune to the effects of aging is an intriguing concept. It is supported by the fact that they must consume the apples of Iðunn regularly to stay young. In other words, this story represents that all are helpless before old age.