We Didn't Start the Führer

""Whatever he was once like, Anu likes destruction now. It's almost as if it relieves his frustration, and it's probably part of his whole addiction to power, as well. But whatever causes it, it's real enough. He and his people certainly proved that a hundred years ago." Colin nodded again, understanding completely. He'd occasionally wondered why Hitler had proved so resistant to assassination[...]. No wonder the bomb plot had failed; a man with full enhancement would hardly even have noticed it. And if anyone had ever shown a maniacal glee in taking others down with them, it had been the Nazi elite."

- Empire From the Ashes: Mutineer's Moon

It is revealed that Adolf Hitler was not just a (particularly disturbed) human being, but was supernaturally evil, and existed with the primary purpose of deliberately going about causing large-scale misery. Aliens may also stand in for supernatural beings. Either way, the message is that World War II was inflicted on us by otherworldly forces, not something mankind brought about by itself.

As befits a trope that's more about the legacy and legend of the War than its actuality, it's often done as backstory for the villain (à la, "How evil is he? Well, you remember Hitler...?"), rather than directly in a World War II setting.

Like Hitler's Time Travel Exemption Act, it could easily be done with other famous warmongers, but in practice almost never is, except as part of a Julius Beethoven Da Vinci where Hitler was also several other famously evil people (in which case, there's a good chance he was also Genghis Khan and Jack the Ripper). At least, this is the case in Western media; Japanese media have something similar going on with Oda Nobunaga.

A form of Beethoven Was an Alien Spy. Can obviously overlap with Stupid Jetpack Hitler and/or Ghostapo.

Anime and Manga

 * The Legend of Koizumi seems to be heading in this direction, as not only does it play Stupid Jetpack Hitler and Ghostapo completely straight (there's a Nazi base on the Moon, for crying out loud!) but Hitler is described as "the greatest sorceror of the twentieth century" and has ridiculous occultic mahjong powers..

Comic Books

 * The French series Mutafukaz has as the Big Bad a bunch of Shapeshifting Cosmic Horrors who have infiltrated all levels of the American government (including the President); their backstory not only shows they helped the Nazi party out, but also at one point killed and replaced him. Fortunately a secret society of Mexican wrestlers saved the day (it's complicated...).
 * In EC Comics' Weird Fantasy #14, the story "The Exile" concerns an alien criminal exiled to Earth. Three guesses what the twist ending is.

Film

 * In Team America: World Police,.

Literature
"What happened to the real Adolf Hitler? Or perhaps you operated from behind the throne--Alfred Rosenberg, perhaps?"
 * In Prince Ombra by Roderick MacLeish, a supernatural evil from beyond time is periodically embodied on Earth to cause trouble. Last time around, it was Hitler.
 * In The Secret Visitors by James White, aliens are trying to wipe out the human race so they can take Earth's riches for themselves. The protagonist learns that Hitler's mania was caused or at least aggravated by the aliens, who deliberately egged him on in the hope that the Second World War would do the job for them. (The first World War was all our own doing, though.)
 * Implied in Operation Chaos by Poul Anderson, where a group of demons in Hell includes one who bears a striking resemblance to Hitler (although the protagonist, being from an Alternate History, doesn't recognise him).
 * In the Callahan's Crosstime Saloon story "Unnatural Causes", the alien Broodseven-Sub-Two Raksha claimed to have been Hitler and the entirety of WWII an alien plot designed to push humanity into developing atomic weapons.
 * The Lensman prequel Triplanetary says that Hitler was actually an Eddorian agent in disguise. The same agent was also Kaiser Wilhelm and the guy who started World War III. (This would require him to be in two places at once, since Hitler and the Kaiser were both alive at the same time, but this is hardly the most implausible thing in Triplanetary, which E. E. "Doc" Smith originally wrote as "a yarn in which scientific detail would not be bothered about, and in which his imagination would run riot". In First Lensman he compounds the improbability, perhaps lampshade-wise, by adding Mussolini to the list.)
 * In the beginning of the Empire From the Ashes trilogy, Hitler is singled out as having been one of the starship mutineers who have been manipulating humanity since the rise of civilization. He was doing it For the Evulz.
 * It seems that Hitler himself was totally human in Night Watch, but he and the Nazis in general were strongly influenced by the Night Watch's attempts to create a utopia. (There have actually been several such attempts, and they all backfired horribly in one way or another.)
 * In another novel by the same author, Autumn Visits, Hitler had a supernatural clone, the Vector of Art, who competed with six others like him (e.g. Stalin's clone, the Vector of Power, who killed and replaced the original) for World Domination and lost.
 * In James P. Hogan's Giants' Star, Terrans discover that a group of humans from another star system have infiltrated us for millennia, teaching superstition and bigotry, trying to hamper our development and later to make us destroy ourselves. During a confrontation, a Terran spokesperson says the enemy intended World War II to be an all-out nuclear exchange, but didn't quite manage it, and asks:


 * Another James P. Hogan book, The Proteus Operation, has it that in himself Hitler did not amount to much - the Beerhall Putch fiasco in 1923 was the peak of his career and in the "original timeline" and he faded into obscurity after some years in prison. The world went on to prosper, the League of Nations was a great success and went on to unify the world, eliminate war and reduce the gap between rich and poor in a worldwide social democratic utopia. But the people who didn't like losing power and privilege went back in time, funded and advised Hitler into power and in 1942 provided him nuclear bombs to conquer Russia - but when the rich people of the past got ready to pack their bags and go to the nice spot which they prepared for themselves in the past, Hitler cut the line and kept the power to himself, engaging in further conquest and genocide in Africa. Then, in the 1970's President John Kennedy in the US, knowing that nuclear war with Germany and Japan was a just a matter of time, that the US was likely to lose and that in any case there will not be much left of the world, sent his own team into the past - whose interference created the world we live in.
 * It is revealed in The Lost Hero, the first book in the second series of books for the Percy Jackson series, that all major world wars are actually fought between.
 * Implied in the latest book that he is actually a son of Pluto, due to looking /very/ similar.
 * Played with quite a bit in Stationery Voyagers. Adelphius Hiltner got his start the usual way. But Varikton Vanqushun began modeling himself after Hiltner and forged an alliance with him. Varikton's tyranny lasted 32 years longer than Hiltner's, and was made up of vampires. Hiltner modernized vampire attire! (Well, at least modernized enough to make them all dress like World War II-era civilians and not dress like Dracula.)
 * For a non-Hitler example, the novel The President's Vampire by Christopher Farnsworth has Osama Bin Laden as a Deep One.
 * Harry Potter strongly implies that the rise of Grindelwald and the First Wizarding War may have had something to do with the Second World War; both events take place during the same time frame and mirror each other in quite a few ways (for example, Grindelwald's imprisonment in a Spandau-like prison).

Live-Action TV

 * The Tomorrow People episode "Hitler's Last Secret" had neo-Nazis possessed by the same alien power that had been Hitler.
 * Related: On an episode of The X-Files, they meet a Jerkass Genie who was responsible for Mussolini's rise and fall.
 * The Star Trek episode "Wolf in the Fold" has an entity that was Jack the Ripper on Earth.
 * In Grimm, an episode had some ancient coins as an Artifact of Doom, giving their holder great charisma, but were addictive and drove the user mad. The hero's partner and later his captain were under their influence, and the villains of the episode were searching for them. It turns out their effects were responsible for Hitler and several other historical Big Bads.

Video Games

 * The ridiculous game Rocket Ranger didn't have Hitler, but it put forth that Nazis were aliens who established their base of operations on the moon.
 * For a non-Hitler example, Oda Nobunaga gets this a lot. The Onimusha series, that one anime "Black Lion" where he's an alien overlord from the future, another anime called Yotoden where he's part of a series of demons in an invasion, and so on.
 * Subverted in Onimusha; Nobunaga starts out as human, gets an arrow through the throat, and is revived by demons to work for them - but winds up taking control of the demons who wanted him for a lackey!

Web Comics

 * The webcomic Good Ship Chronicles reveals that Nazi jokes are no longer PC as it was discovered all Nazi activities were the result of an alien mind-probe.

Comic Books

 * In The Ultimates, it's revealed that aliens were highly involved with the Nazis. However, it's unclear how much of what the Nazis did was their idea, and in fact it seems like the Nazis had a greater influence on the aliens, as post-WWII, the aliens mention that they kept the Nazi uniforms and symbols because they liked them.
 * It is also implied that the aliens did not really approve of the racism and death camps, regarding them more like forgivable excesses for the greater good which, to the aliens, was the eradication of individuality.

Film

 * Downfall took some criticism in Germany for portraying Hitler as a flawed and broken human being rather than a Complete Monster. The director actually invoked this trope in his defense: if we continue to act like Hitler was some alien monster teleported to earth to do bad stuff, we as a nation and a race are never going to learn from the past.

Literature

 * Played with in the Doctor Who New Adventures novel Timewyrm: Exodus, where Hitler separately receives covert assistance from two different groups of aliens attempting to further their own ends—but neither is able to control him, and what he does with their assistance is all entirely his own idea.

Tabletop Games

 * Inverted in the classic Old World of Darkness. The creators felt putting one of the (many) supernatural groups in the Fantasy Kitchen Sink behind the Nazis' horrors would be in bad taste. Which leads to a very strange situation where, in the Crapsack World that is the World of Darkness, World War II is the only event in human history that wasn't in some way manipulated by the supernatural. That's not to say they didn't take sides, they just weren't running the show the way they'd have you believe they were for almost every other historical event.
 * Similarly averted in In Nomine Satanis/Magna Veritas, as well as their American version, In Nomine: Although some notable historical events (such as the Crusades) resulted from celestial or infernal intervention; Hitler's actions were independent and a complete surprise to both Heaven and Hell.

Video Games

 * Played with in Persona 2: Innocent Sin. Hitler is apparently revived using the power of rumors and a conspiracy theory that he escaped the bunker instead of committing suicide; however,.
 * In the Assassin's Creed Alternate History, Hitler was actually . In an interesting twist, , and the entire point was  . It is worth noting that in one of the letters than can be read in the game,  . And they would have gotten away with it too, if it weren't for those darned Assassins!

Real Life

 * Completely averted in post-war Germany. Common consensus and official position is that the rise of Hitler and his rule were merely a symptom of German society at the time. If it had not been him, someone else would have assumed the role and things would have turned out mostly the same.