Since the mystical hammer Thor, it has been ed from hero to hero throughout the universes of both Marvel and DC Comics. So much so, that it's difficult to even define what makes one hero -- or one villain -- able to carry it, and another forbidden.
When you make such a massive weapon open to anyone from anywhere, so long as they be "worthy" that's the kind of mileage you're going to get. But there have also been several characters to wield Mjolnir that seem... less worthy. But the truth is that most of these seemingly-broken Mjolnir moments have been due to devious life hacks in the Marvel universe. Still, these moments that defy reasoning tend to be pointed to as exceptions which break the rule, so let's get to the bottom of some of the most famous examples.
While comic book fans are quick to point out that every character who has raised Mjolnir. And not all of them have been even mostly good.
For example, his mutant children Scarlet Witch and Quicksilver in The Ultimates 3 #5, Magneto was able to lift and use Mjolnir, but manipulating the energy around the hammer with his ability to control electromagnetism. Though this wasn't necessarily him hoisting the hammer above his head in his fist, he did still technically lift it without being a truly worthy hero (which isn't supposed to be possible).
The same is true for the circumstances around Red Hulk lifting the weapon. In Hulk Vol. 2 #5, Red Hulk again technically lifted Mjolnir by doing so in space. Since the enchantment on the hammer is based on weight, it doesn't work in space's lack of gravity. Therefore, the character with super-strength was able to lift it with ease and fight Thor (that's got to sting). Another character, Awesome Andy AKA Awesome Android was also able to wield Mjolnir despite being the invention of evil inventor Mad Thinker. His role is to do whatever the villain commands, but he is able to absorb others' abilities and talents in order to become more powerful. By absorbing Thor's nobility, he was able to lift Mjolnir without proving himself worthy beforehand.
The most recent and notable example came during Secret Empire, when Hulk himself, who just lifted Thor holding the hammer instead of lifting the hammer itself.
Basically, you can lift Mjolnir without being worthy, but you can't wield it easily and it's going to require outer space, electromagnetic manipulation, or being an android that can absorb traits of others. If not, you're better off just whipping Thor around while he holds it, and hoping for the best.
