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The killer in your attic - It's a tale as old as time. We've all heard stories involving a potential killer living in our attic who comes down when everyone is peacefully asleep. But this has actually happened.

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The killer in your attic - In Germany in 1922, a farm owner named Andreas Gruber noticed that small things started going missing or being misplaced. His family also heard footsteps while Gruber himself found footprints in his house.

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The killer in your attic - A few weeks later, the entire family was found slaughtered in their home. The identity of the mysterious killer remains unsolved.

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Le Loyon - Residents of the areas surrounding the Maules Forest in Switzerland told stories about a mysterious man who walked around the woods wearing a long camouflage cloak and a gas mask.

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Le Loyon - He was named the ghost of Maules or Le Loyon by the locals. But with no proof of his existence, it was all brushed off as folklore.

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Le Loyon -

In 2013, however, a passerby snapped this photograph of Le Loyon. Not long after, his cloak and gas mask were found in the forest with a note saying he couldn't take being seen as a monster. It is unclear what happened to him, but he was never seen or heard from again.

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Charlie No-Face - If you're an American from the Pittsburgh, Pennsylvania area, chances are you've heard about Charlie No-Face, a faceless man who wanders the roads at night.

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Charlie No-Face - The story says the man was a utilities worker whose face melted in an acid attack or an electric accident, depending on who's telling it.

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Charlie No-Face - But, the truth is, the man was real. His name was Raymond Robinson and he was the victim of a childhood accident that completely disfigured his face. He, understandably, avoided crowds, opting to go for strolls at night.

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The Night Doctors -

Also known as Night Riders and Ku Klux Doctors, they represent a sort of boogeyman in African American folklore. The tale says that doctors looking for victims to experiment on would lurk in the dark, waiting for the opportunity to kidnap them.

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The Night Doctors - The rumors were spread by whites who were trying to prevent the former slaves from moving to the north. Unfortunately, the boogeyman has some factual basis.

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The Night Doctors - There is some evidence that 19th-century doctors were performing experiments on members of the African American community. White farmers used this as a scare tactic against black people, a technique that was picked up by the Ku Klux Klan after the Civil War.

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The Alice Murders - A more recent tale has been circulating in Japan, which deals with a supposed five slayings between 1999 and 2005. In each case, the killer wrote the word "Alice" nearby.

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The Alice Murders - After killing and mutilating the victims, the killer also left a playing card. But these murders never actually happened—at least not in Japan.

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The Alice Murders -

A convicted murderer terrorized Madrid, Spain, in the early 2000s following a similar method. Alfredo Galán shot and killed six people, leaving a playing card on the body before fleeing the scene.

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The Legend Of Cropsey -

A boogeyman-like creature in Staten Island, USA, named Cropsey was said to be an ax-wielding murderer who escaped from a mental institution and lurks in the tunnels below the old Willowbrook State School—a former facility for children with intellectual disabilities that was shuttered after allegations of horrific torture and mistreatment were exposed.

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The Legend Of Cropsey - The story says Cropsey comes out at night to snatch children, bring them back into the abandoned Willowbrook, and kill them. The legend, however, is more real than it sounds.

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The Legend Of Cropsey - Andre Rand, a suspected murderer who was convicted of kidnapping two children in the 1970s, as it turns out, worked as a janitor at Willowbrook in the mid-1960s.

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The Puebla Tunnels - For hundreds of years, the residents of Puebla, Mexico, told folk stories about a mysterious network of tunnels hidden underneath the city.

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The Puebla Tunnels - But that network of tunnels simply didn't exist. Or did it?

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The Puebla Tunnels - In 2015, a crew of construction workers found a mysterious tunnel. Since then, about six miles of mysterious tunnels, believed to have been built between 16th and 19th centuries, have been discovered snaking under the city.

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The babysitter and the man upstairs - The tale of the babysitter who receives an eerie phone call only to discover the call was placed from inside the home has been popular since the mid-20th century.

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The babysitter and the man upstairs - The story has yielded several films, including 'When a Stranger Calls' (1979) and its spin-offs.

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The babysitter and the man upstairs - The story is based on a real-life crime that took place in 1950 in Missouri, USA. A 13-year-old named Janett Christman was babysitting a three-year-old boy at his home when she was brutally raped and murdered by an intruder. Her case remains unsolved.

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The Bunny Man -

The legend of the Bunny Man that haunts Virginia, USA, and the surrounding area says that, in 1904, a bus transporting patients from a mental institution crashed, killing everyone but 10 patients. A search party found all but one of them.

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The Bunny Man -

That's when carcasses of bunnies began to be found hanging from a nearby bridge. Later, the corpse of a man was found hanging in a similar fashion. Needless to say, the Colchester Overpass in Clifton, Virginia, is considered haunted.

The legend is thought to have drawn inspiration from two incidents, the second originating in the 1970s when a man in a rabbit costume threatened people with an ax.

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The Hookman -

This urban legend has countless variations, but they all start with a couple making out in a car on a deserted road. Then the radio crackles, and a news report interrupts the romance to tell listeners that an escaped killer with a hook for a hand is on the loose.

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The Hookman -

What happens next varies widely, but you get the picture. As much as this sounds like the script of a B movie, it actually happened in the USA, in Texarkana, Texas.

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The Hookman -

In 1946, a series of murders known as the Texarkana Moonlight Murders took place in the city. The "Phantom Killer" attacked eight people, killing five, all of whom were in cars on what is known as "lovers' lane." The murders were never solved.

See also: The biggest regrets of American presidents

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