Mjolnir

Mjolnir is the magical Uru hammer wielded by Thor. Mjolnir can only be picked up by those it deems worthy. After Thor was defeated by Ego, Mjolnir went to Earth to bring the Fantastic Four.

Background
In the comics, Mjolnir can be wielded by Captain America, Wonder Man, Beta Ray Bill, and Odin. In the Ultimate universe, Hulk can pick it up only through his immense strength.