Mjölnir

Thor
When the God of Thunder disobeys his father orders and attacks Jotunheim, Mjolnir proves to be useful against the towering Frost Giants, and gives Thor enough power to slain many of them.

When Odin intervenes, anyway, he chooses to banish his son to Earth, so that he can learn some humility, and casts a spell on Mjolnir, declaring that it won't come back in Thor's hands until he proves to be worthy of it. Sent to Earth along with Thor, Mjolnir lands in New Mexico, where is found inside a crater by some people living nearby. The citizens starts a contest, trying to lift it, with no results: a man tries to move it using his pickup, thus breaking the car. Later, Phil Coulson finds the hammer too, and builds a S.H.I.E.L.D. research center around it.

When Thor arrives to claim his weapon, he cannot lift it either, since he has still to become a humble and noble man, instead of the proud and belligerent warrior he is. Loki then tries to lift it too, hidden from the S.H.I.E.L.D.'s agents' sight, but obviously fail. When The Destroyer attacks Earth and Thor sacrifices himself to stop it, Odin's spell is broken and Mjolnir flies to his original wielder. With Mjolnir in his hand, Thor easily defeats the Destroyer and comes back to Asgard, where the last battle with his brother awaits. Using the power of Mjolnir, Thor destroys Bifrost Bridge, thus preventing Loki to destroy Jotunheim.

Powers and Abilities
Mjolnir is the weapon used by Thor, a magic hammer forged into the core of a dying star, the perfect weapon for the new ruler of Asgard. Mjolnir gives its wielder the power to rule over storms and to fly, able to be thrown as a long-range weapon. It can be lifted only by worthy masters, namely Thor.

Appearances

 * Canon
 * Iron Man 2 (cameo)
 * Thor