-Under Constuction-Magneto leads the Brotherhood of Mutants, and usually opposes the X-men. He has the mutant ability to control metal, and anything magnetic. Pretty badass.
Magneto made his debut in 1963, in X-Men issue 1. He was intended to be their long-term nemesis, and was so for a long time. Leading the Brotherhood of Evil Mutants, he would routinely interrupt classes at Xavier academy, and cheat at pinball.
With all the young mutants wandering around (a seemingly endless supply), obviously some of them are going to be "good guys" (those who see humans as equals) and "bad guys" (those who see humans as inferior). This equality business defines a lot of the struggles within the X-men universe, and Magneto is often right at the focus of the tension, helping it along.
Magneto's actual power is to be able to generate and control magnetic fields, and manipulate existing fields. It turns out this can do a lot more than just bend metal. One of his most frequent tricks is an electromagnetic force shield, which can stop most projectiles, and well, most anything. Nuclear warheads have struck the field before, but Magneto is so powerful that he still emerges unscathed.
The Dark Side actually stole most of it's cool moves directly from Magneto.
He also wears metal boots, and usually clothes with metal plates in them, because he can then pick himself up and glide around wherever he wants. Magneto is rarely seen walking anywhere, and usually approaches hovering 4 to 6 feet off the ground. This is one of the little things that help people realize that he's the leader.
His second-in-command is Mystique, a blue skinned woman who can shapeshift into looking like anyone, as well as temporarily armoring herself or increasing her muscle mass. When it seemed that Magneto was dead, Mystique took over the Brotherhood of Mutants (which eventually dropped the "Evil" from it's name for tax purposes) until he returned.
Despite wanting to conquer and enslave humanity on many occasions (but then again, who doesn't?), it was eventually revealed that his motives were actually...kind of good? It seems that as a child, he was in a concentration camp, even before he knew he was a mutant. Being treated with utter disregard and cruelty merely because he was of gypsy descent did not sit well with him. At all. Seeing humanity at it's worst, he could never unsee it, and it made him highly bitter, and defensive of his fellow mutants.
In essence, Magneto does whatever he thinks is necessary to make sure that no one ever rounds up mutants and starts exterminating them.
As homo sapiens, it might be easy to think "Well, I don't want evolved people getting to tell me what to do!", but the fact is, nature seems to be on Magneto's side. Consider how the large monkeys dominate the small monkeys. Now consider how humanity dominates all the monkeys. It doesn't seem that this branch of evolution does anything but wield it's power over those without it. Don't worry, you're probably not a horrible person for not letting monkeys make any big decisions in the world. The point is, Magneto really isn't a bad person for not wanting humans to make any decisions. He's just not on your side. There's a difference.
Magneto and Xavier have a long history of friendship, but Stan Lee had actually considered making them brothers early on. Lee admitted in an interview that while he created Magneto to oppose the X-Men, he never saw him as a villain. He wanted to highlight how discrimination and prejudice happens in the world, and he wanted to show that it does have an affect on people. By giving Magneto a good motive but merciless methods, Lee truly succeeded in depicting a struggle that couldn't simply be defined as black and white.
There was really no way to make any kind of X-Men movie without putting Magneto in it. Well, there was one script without him, but it was horrible and stupid, and it involved a karaoke contest at Xavier Academy. We are very happy that one was never made.
Here Magneto waves hello to...oh, nope, he made their guns bend up and explode. Nevermind.
Sir Ian McKellen played Magneto in all 3 films, and did an incredible job of it. If you don't see how an old white British man could possibly understand being a marginalized outsider, then you probably didn't know that he is also openly gay.
Not just regular "openly" either. More like "completely sick of homophobic bullshit". He never made his own personal life a secret from other actors, but after he came out, he decided to try to do something about the existing anti-homosexuality laws in Britain.
After meeting with a govenment official and asking him to lobby in favor of removing the law, he was turned down, and the politician refused to budge on the issue. When McKellen went to leave, the man asked him for an autograph for his family. Rather than just kicking the man straight in the balls, McKellen smiled and agreed, then instead wrote "Fuck off, I'm gay.", which we assume the man did not then give to his children.
In short, if McKellen had Magneto's powers, he'd probably be hovering around Uganda right now, shouting at people and fucking shit up left and right, and extricating his fellows from the prisons there. We really wish there was a way to make this happen.
Magneto's character came across well enough in the first 2 movies, but the terrible confused writing of the third one seemed less intent on keeping him consistent with the source material. Sure, plenty of X-men fans stamped out of the theater in fits of nerd rage during the first movie ("No! Rogue is not a child. She is in her 30s. It's clear that the director did not read the comics!!!"), but the 3rd movie even made some of the more chill fans make a face and go "What?".
For most people, it was the scene where Mystique loses her powers and becomes human, and instead of freaking out with concern for one of his best friends and longtime right-hand woman, and trying to help her get her powers back as fast as possible, he just kind of says "Oh, too bad for you!" and walks away. This would be like if the Wicked Witch lit the Scarecrow on fire, and Dorothy was just like "whatever dude...I guess it sucks to be made of straw...."
The problem isn't so much that you can't take a villain and make him into an antihero and then make him back into a villain. The problem is that whatever they do has to make some kind of pyschological sense. It doesn't even have anything to do with superheroes or mutants, it's just kind of a thing that exists in all movies and books. If it doesn't make any sense when it happens, and then you finish watching the movie, and now it makes even less sense...that probably means it wasn't a very good idea.
It seems that one of the next few X-Men movies will be Magneto:Origins. Let's hope like hell that it's better than the Wolverine:Origins movie was. Please let it not be like that. There may be more nerd rage pending.
It may seem obvious that Magneto is in almost every X-Men game, but what his most hardcore fans really care about is him being a playable chacter in X-Men Legends II (and some versions of Marvel Alliance 1&2).
If you've ever wanted to run around causing rampant magnetically-generated destruction, this game is probably your best bet. You are limited to only 4 special attacks, but so are all the other characters, so you can hardly complain. All you really get to do is beat up bad guys, wreck all the crates you can find, and pick up glowing mutant Lucky Charms marshmallows. Obviously, one color restores your health, one recharges your mutant energy, and one just kind of sticks in your teeth. Actually, we can't really tell what the little glowing things are most of the time, we just know you have to pick them all up or else it's considered littering.
I guess it's a shitty day to be made out of metal.
Still can't get enough of his red-cloaked magnetic might?
There have been plenty of Marvel cartoons so far, and Magneto has actually appeared in many of them. The X-Men cartoons probably have more appearances by him than any other series, but it would be kind of dumb if they didn't. They're kids' cartoons anyway, so don't expect to see a terribly faithful adaptation of the comics.
There's some kind of Marvel Hero card game, and Magneto is in that too, but now we're kind of pushing it.
We really hope someone out there also makes a Magneto refrigerator magnet too. It just makes too much sense not to do it. We would definitely put Magneto on our fridge.