The rule of Thor's mystical hammer is simple and straightforward: whosoever holds this hammer, if he be worthy, shall possess the power of Thor. That's the message emblazoned on Mjolnir, but it gets a little less clear-cut in practice; the determination of worthiness decided by an inanimate - if magical - object can be easy to shift one way or another as the plot requires.
Despite being in a world populated by powerful superheroes, not everyone has the purity of intent to wield the Norse god's trademark weapon. Even Thor himself had to prove his worthiness to his father Odin to receive the hammer – and he's lost it a fair few times through the years, too. Worthiness isn't a fixed trait, but rather something that depends greatly on circumstances, which can change with time. Because of that, many characters lifted Thor's hammer –some through loopholes, some thanks to cheating. But no matter how they did it, they all got a taste of that power for a or two.
Updated on July 12th, 2022, by Shawn S. Lealos: Thor: Love & Thunder will introduce the world to a new Thunder God, as Jane Foster will finally take up Mjolnir and become the new Thor of Earth. This comes straight out of the comics and it will lead to a battle where Thor and his allies battle the God Butcher, Gor. In the MCU, fans have already seen Captain America and Vision lift Mjolnir, and while Jane is the first person to show her worthiness, there have been several in the comics. There were even two event series that hit Marvel in the last two years that saw heroes prove they could wield the magical hammer for very different reasons. Regardless of who has lifted Thor's hammer, it often shocks the actual God of Thunder.
Squirrel Girl
No one can beat Squirrel Girl. She is unbeatable, and that is actually part of her title. However, she is also someone who has proved worthy of wielding Mjolnir. This happened in The Unbeatable Squirrel Girl Beats up the Marvel Universe, which was a take on the books where someone like Deadpool or Punisher kills the Marvel Universe. It's just nicer.
In this series, Squirrel Girl faced a clone of herself. The clone had beaten the Avengers and Squirrel Girl showed up to fight back. She saw Mjolnir and picked it up, becoming a new Goddess of Thunder, and one of the most surprising people who has lifted Thor's hammer.
Moon Knight
In the recent Avengers storyline The Age of Khonshu, Earth's Mightiest Heroes had to battle two god-like beings. One was Mephisto, a demon that was intent on taking over the world. The other was Khonshu, who had declared himself Earth's protector and decided he should take over the world to protect it from Mephisto.
The Avengers needed to stop both, and that put them at battle with Khonshu's avatar Moon Knight. In the battle, Thor launched Mjolnir at Moon Knight, who then stopped it in midair. He then explained that he had the power of the moon god and that Uru, the metal that created Mjolnir, was made out of moon rock - meaning he was someone else who has lifted Thor's hammer.
Doctor Doom
Not everyone who has lifted Thor's hammer was worthy to hold Mjolnir. A perfect example of this is Doctor Doom, one of the world's most dangerous villains. While Doctor Doom is a master of magic and science, it was his luck in finding the hammer that allowed him to wield it.
Mjolnir fell into Hell. When it was in that realm, the mystic protections collapsed and Doctor Doom was able to pick it up and use it to escape Hell and return to Earth. Once back on Earth, he was no longer able to wield the hammer.
Eddie Brock
In the recent King in Black Venom crossover series from 2020 to 2021, Knull set his sights on destroying the entire universe. The far reaches of space saw heroes like the Guardians of the Galaxy and the Kree-Skrull Empire fighting the dark god's forces, but when Knull finally targeted Earth, he met his match in Eddie Brock, whose symbiote, Venom, was part of a race that Knull created.
However, Eddie Brock got more help than that when the battle heated up. After almost dying, the cosmic entity, the Enigma Force, revived him and powered Eddie up. He then was able to do many amazing things, including using Silver Surfer's board and wielding Mjolnir, using them to create a battle axe to even the odds.
Deadpool
Anyone familiar with the wisecracking, fourth-wall-breaking mercenary Deadpool might raise an eyebrow to hear that he once was someone who has lifted Thor's hammer. The entire ordeal was orchestrated by Loki, Thor's adopted brother and perennial thorn in his side, who manipulates Deadpool into stealing the hammer. Deadpool does so while Thor is on a heroic mission. Thor drops the hammer and Deadpool takes advantage of the relative chaos to locate it first.
Deprived of the object that allows him to transform into his godlike form, Thor takes on the appearance of his human alter ego and Deadpool is suddenly sprouting a cape. However, there is a catch: Deadpool wasn't actually in possession of the real Mjolnir. The real one was still lying where Thor had dropped it, made invisible by Loki, who also created the false one that would give Deadpool the illusion of Thor's powers and in the process cause a lot of trouble for everyone.
Beta Ray Bill
Hailing from an alien from a race known as Korbinites, Beta Ray Bill became a partial-cyborg protector of his home planet after it was decimated by a demon from Thor's homeworld Asgard. On a mission to find a new place to live, Bill came into with Thor himself. They fought and Mjolnir got away from Thor, which is when Bill discovered he was someone who has lifted Thor's hammer. There was no trickery involved; it was purely because he was worthy and wanted to use it to protect his people.
Odin recognized this and decided the fair way to resolve this situation would be for Bill and Thor to fight it out – again. Bill won again, but that didn't mean he got to keep the hammer; instead, Odin created a new hammer for him called Stormbreaker that Bill could wield himself.
Rogue
The Marvel What If…? series explores storylines that differ slightly from the accepted canon, diverging at important moments and delving into an alternate reality. One such story takes the moment when Rogue and the Brotherhood of Evil Mutants attack the Avengers. In the regular canon, Rogue's ability to absorb the life force of others had her zapping Carol Danvers of her powers and vitality.
Instead, What If…Rogue Possessed the Power of Thor? had Rogue do the same to Thor, killing him and in the process gaining enough of his intrinsic Thor-ness to be someone who has lifted Thor's hammer. Rather than being worthy on her own, Mjolnir seems to recognize her as Thor. The resultant surge of power kills Vision and Iron Man and also leads to the deaths of everyone in the Brotherhood. Rogue is understandably at a very low place, but a visit from Thor's spirit convinces her to honor her new position as the Goddess of Thunder and do some good with it.
Conan the Barbarian
Another issue of What If…? brought Thor into with Conan the Barbarian, a sword-wielding character who existed in a time between cavemen and ancient societies. Both characters lived in similarly fantastical settings and were considered great warriors, making a run-in between the two plausible. Thanks once again to Loki's troublemaking, Thor ended up in Conan's land Hyboria with a bad case of amnesia.
Thor and Conan met and became friends, but Mjolnir is lost during their adventures. The hammer is found by the villain Toth-Amon, and in the fight to get it back, Thor causes them both to be struck by lightning. The villain dies, but despite being the God of Thunder, so does Thor. He leaves Mjolnir to Conan, who is able to use it to become a god.
Magneto
Marvel's Ultimate Universe is an alternate world that is known for its darker and grittier take on familiar heroes. In that world, Magneto lost his children Quicksilver and Scarlet Witch and the ensuing grief drove him to extreme actions. Magneto's electromagnetic powers gave him the ability to manipulate all kinds of metals, and it turned out that Mjolnir was no exception to Magneto's sphere of influence.
Magneto wasn't someone who was actually able to lift Thor's hammer, but he was able to manipulate the air around it to much the same effect. However, in the main Marvel universe, Magneto is unable to control Thor's hammer at all. The hammer is forged from a particular metal not native to Earth called Uru, and because it is not native to Earth, it's less able to be controlled by Magneto.
Thunderstrike
Eric Masterson has the makings of a very traditional heroic backstory: he was a very normal man who found himself in extraordinary circumstances and rose to the challenge. Eric was just a regular guy, a construction worker when he came into with the God of Thunder. He was the collateral damage in a throwdown between Thor and the villain Mongoose.
Odin recognized Eric's intrinsic decency so he saved his life in the only way he could: Odin merged Thor and Eric into one person. For a while, Eric functioned as Thor's identity any time Thor needed to be a civilian and this was how Eric was able to use Mjolnir. Eventually, Thor and Eric separated, with Odin forging a new weapon just for Eric: a mace called Thunderstrike.
