Introduction
Magni ("mighty" or "strength") is a son of Thor, remarkable from earliest childhood for his extraordinary strength, and one of the gods prophesied to survive the destruction of Ragnarok, inheriting his father's hammer Mjolnir afterward.
Family
Childhood strength
In a story told of Thor's battle with the giant Hrungnir, Thor was pinned beneath the giant's fallen leg after the fight, and none of the assembled gods could lift it off him. Magni, then only three days old, came and lifted the leg with ease, remarking that he was sorry he had not arrived sooner, since he could have dispatched the giant himself with his bare fists. Thor rewarded him with Hrungnir's horse.
Survivor of Ragnarok
Magni, along with his brother Modi, is prophesied in the Poetic Edda's Voluspa to survive Ragnarok and inherit Mjolnir, continuing something of their father's legacy into the renewed world that follows the destruction.
Parentage
Sources disagree on Magni's mother, with some naming Thor's wife Sif and others the giantess Jarnsaxa, a discrepancy the sources do not resolve.