Nisser, the Danish, or rather Scandinavian, small and cute gods of protection. As far as I know, the nisse can form when an old farmer dies and is buried on their farm. The nisse will then henceforth protect the farm and it's inhabitants.

Now, while considered fun and cute in modern times, the gårdsnisser (contrary to the more feral and much more dangerous skovnisser/forest nisser) are very gullable with a strong sense of guilt, and they are hotheaded and intractable/stubborn to an unreasonable degree. They will protect you and give good luck if treated well, but will be intolerable if they feel inconvenienced or not properly cared for, to the point where they might directly or indirectly kill everyone on the farm out of spite.

Sometimes they cause atrocities because of misunderstandings, and when finding out that it was a misunderstanding on their part will cause harm to others to make up to their own farm, such as stealing cattle from neighboring farms to make up for the cows they killed earlier.

Now, the possibly worst thing you can do is to try and force a nisse to show itself to you. The small creatures accept indirect gifts, but don't like direct contact and have a cursing bite, and will most definitely bite if cornered, such as by a nosy and persistent child. This curse makes one fall sick, loosing health and strenght until one perishes in a matter of months/years. As far as I'm aware, there is no cure for the curse, and regarding the nissers tendency to be fooled or act before thinking, well....

Having a nisse on your farm can be a great blessing, but one is also constantly in danger of having their whole family killed over a minor misunderstanding or mood swing. So it is heavily recommended not to acquire any farms where a nisse might reside.

We have the ättestupa in Sweden - the idea that we pushed the elderly off a cliff when they got old.

In Bengali folklore, we have this thing called Nishi. It's a nocturnal spirit that wanders around, and calls people by name. She'll knock on your door, and call you by name. If you answer, you're placed under her control. And she'll take you to some remote location, and kill you. It's also said that if she calls you 3 times, and you hear all 3 calls, there's no way you can resist answering her.

In my childhood, sometimes people would be found passed out in the forests, and it'd be attributed to the Nishi. I think that they were just drunk/high, and went along with it when the others said it was Nishi.

There's a Hindi horror comedy movie named Stree on a similar folklore from another part of India. It's pretty good, would recommend it.

Irish folklore has lots. Banshees are pretty famous. It’s a ghostly wailing you hear at night. When you hear it someone dies.

One of the nicer stories is children cursed to be swans instead of people due to an evil stepmother. They end up outliving everyone and moving to the land of youth, as swans.

Fairies are evil.

Butterflies are a link to the other world.

Hell is cold, as a hot hell, like Christian hell, was considered to provide a small amount of comfort.

https://en.m.wikipedia.org/wiki/Bunyip

If you were worried about dingos and drop bears when coming to Australia then you don't want to know about the bunyip.

It'll fuck you up.

Near Antigonish in Nova Scotia is a forest called Dagger Woods...the sign is right on the main highway. The story goes that a young lady was killed there a few centuries ago and you can hear her screams. First far away and then it slowly gets closer and louder till it's piercing loud. Nothing bad happens but super freaky!

The Saci-Pererê is a Brazilian folklore about a one-legged man who lives in the forest, and loves to play tricks on people. He uses his cap* (autocorrect) to disappear and reappear elsewhere, sets animals loose, steals kid's toys, etc. Not scary but it's what came to mind.

One thing I could think of from Filipino culture is the manananggal (rough translation: one who removes). It's a sort of humanlike being, but with wings and a very long tongue. At night, its body from the waist up would fly away and leave its lower half behind, then it would hunt for food. It would go on top of pregnant womens' rooftops and using its long tongue it would feed on the fetus. Once the manananggal gets back to its lower half, the fetus would be gone forever.

In order to get the fetus back, you can prevent the manananggal from returning to its lower half by putting something on the lower half, if you find it (not sure if it was salt or garlic or something else).

One interesting thing that I'm not sure is quite related, but if you have a miscarriage, people say that 'nakunan ka' (rough translation: you were taken from / x was taken from you). Could be left over from the idea that the manananggal takes fetuses?

Not sure how such an outlandish tale captivated so many people for so long, but: Trickle-down economics.

Some Salish tribes told stories of the basket ogress which was a disheveled woman who would come and steal misbehaving children, throw them in a basket, and eat them. She was also venerated as bringing wealth.

In Finnish folklore there's a couple of scary things but the one that pops to my mind is the water spirits. Näkki, vetehinen and hiisi. They are all slightly different but all have basically been used to scare kids to stay safe around waters or the water spirit of your choice will drown you. There's stories of them attacking boats too and trying to trick adults into drowning themselves.

Oh, I've got one.

In Romania, on June 24th there's the "Sânziene" day. Which are like fairies. Google sources say they're good, love/fertility fairies but there's folk stories that say you shouldn't swim during that night because they might come and take you (by drowning you).

My grandpa would tell this one:

There once was a man who lived all by himself way out in the woods. He lived in a small log cabin with just one room, and that room served as his kitchen, dining room, parlor, and his bedroom too. This man owned three great big hunting dogs. One was called You-Know, one was called Eye-Know, and the third was called Cumptico-Calico.

One winter night the man had run out of food and had to go to bed without supper. Just as he was starting to drift off to sleep, he snapped his eyes open at a noise. He looked around and there in the cabin with him was the curiousest creature that you ever did see. It has two little pointed ears, and two great big red eyes, and it had a great big long tail. The man snatched up his hatchet and swung at the creature, chopping off it's tail. The creature shrieked and fled back out into the wilderness.

The man cooked and ete the tail for his supper and then went back to bed.

An hour or so later the man wakes with a start. Way out in the distance he hears something call out, "taily-po! Taily-po! All I want's my taily-po!" The man called out to his dogs, and they came barrelling around the side of the cabin and chased the whatever-it-was far away from the cabin. Only two of the dogs came back.

Later that night, the man awoke again. Something called out, "taily-po! Taily-po! All I want's my taily-po!", only from nearer than before. The man called out to his dogs again, and the two dogs crashed across the meadow chasing the whatever-it-was even farther away than before. But this time only one dog came back.

In the deep, dark hours of morning, the man woke again. And from just outside his front door he heard the whatever-it-was demanding again: "Taily-Po! Taily-Po! All I want's my taily-po!" The man called out to his last dog, who chased the whatever-it-was for miles and miles and never came back.

Just before daylight the man woke once again. He didn't hear anything, but when he looked down at the foot of his bed he could see two little pointed ears. And after a moment two big, red, fiery eyes were looking at him. Slowly the whatever-it-was crept up the foot of his bed until it was right on top of him. And in a low voice it said, "taily-po. Taily-po. All I want's my taily-po."

The man found his voice and screamed, "I ain't got your taily-po!"

But the whatever-it-was replied, "yes, you has!" And it jumped on the man and scratched him all to pieces!

Some say it got its taily-po back; some say it didn't. But when the moon shines bright and the wind blows down the valley, you can sometimes hear a voice cry out, "taily-po!"

Here in Northern Italy near Bergamo, we have something called "Gratacornia", an half human-half goat creature, which was used to scare kids. The Gratacornia waits for the kid on top of the stairs in darkness and scratches his hooves with his long horns (Gratacornia is formed merging "Grata"=to scratch and "Cornia"=horns).

I lived in Hawaii for a short time. Stories of the night marchers messed me up for a while. They also had a lot of Japanese folklore that got tangled up there too. Calling ghosts are fucked up too.

We have few, but you probably know them already from playing Witcher

I live in New Jersey. Most people know it for the sopranos or even just the turnpike, but in the south of the state there’s a huge pine forest called the pine barrens. The Lenape that originally lived in New Jersey spoke of a spirit in the forest known as M’Sing, a deer like creature with leathery wings.

After New Jersey was colonized, a legend came out of a family that lived in the barrens in the 18th century, the Leeds. Mother Leeds, upon finding out she was pregnant for a 13th time, cursed the child. It is said she gave birth during a terrible storm. When the child was delivered, it transformed into a creature, not unlike what the Lenape described. It quickly took off out of the chimney and disappeared in the forest. Since then, people spot the “Jersey Devil” throughout the state, but especially around the pine barrens. Personally, everything I hear the thing is harmless, but creepy.

Here in Australia, it's drop bears, but they're less folklore and just more... difficult to find. Until it's too late, of course.

Here in Costa Rica we have plenty of those:

• El Cadejos (the chain-hound): a black dog wrapped in chains, said to appear in the night to scare drunkards straight, and allegedly a former drunkard itself.
• La Segua (or La Cegua): a woman that seduces men at night, then shows her true form as a human with the head of a horse, an event which is said to scare men to death.
• La Llorona (the crying lady): a woman who lost her child, by drowning in a river in several sources, and cries loudly for that during the night.

That they can't make poutine right in the US.

Czarny Roman (Black Roman), a homeless guy from my town, who used to wander the streets in a dark suit and hat (in winter he switched to neon-coloured ski robes). The story goes he used to run a black-market currency exchange in the 80s and was terribly rich, but either a business partner fucked him over or he lost it all at a casino; he went nuts and ended up on the street. A different story says he ran a coffee shop with his ex-wife. Some claim he used to study at the University here or even the Fine Arts Academy. He had a family (they were interviewed at his funeral by the press) who reside in New York and probably only they know the real story. He was strongly against drugs, cigarettes and alcohol; aparently used to discourage kids from smoking. He wilfully gave up social housing and spent many years wandering about and talking to people about art, poetry, music, yoga and death. He claimed he was immortal and once left a note on a napkin which gave a glimpse of his early life. Apparently he was born in 1950 and his mother was murdered by his father. He claimed Warsaw will be hit a with a meteorite and claimed to know the dates of death of passerby's. He never begged for help, even had his own food and was sometimes supported by people he talked to. I've never talked to him myself but he was on a "good morning" basis with lots of people here and seemed to be able to remember them well.

wiki article in Polish

some article about him released soon after his demise, also in Polish

some forum post about him, Polish as well

a music video with him (around 2:50)

My area has a supposed undead creature called Stovepipe. He has a stovepipe stuck in his head and attacks people by train tracks. Apparently he died in a terrible accident and couldn't move on because he was so mad about his death. High schoolers love going looking for him lol. I don't believe he exists, but it's an interesting thing.

In Louisiana we have the rougarou that’ll come and get ya if you don’t act right.

https://en.m.wikipedia.org/wiki/Rougarou

He’s similar to a werewolf, but French.

I'm from New Mexico, which is steeped in Native American culture. One of the cultures is the Navajo culture, which features the terrifying Skin Walker.

i grew up in East Anglia, which is the hump on the east-by-south-east side of England, UK, British Isles, Europe, Earth, etc

not only did we have the super cool Hereward the Wake, and Boudic(e)a and the Iceni tribe

but also

• devils dyke — a seven mile ditch caused allegedly by the devil himself being turned from a wedding and stomping his tail, and you can summon him yourself by walking around the local church 7 times

• fairy cow — a magic cow who gave milk to all in times of famine stamped her hoof in the sandstone and the.imprint is still seen today

• devils hole - a place where such a horrific crime was committed that when it rains the ground never gets wet

• tom hickathrift - a 1700s legend of a giant-killing giant whose catchphrase was "a turd in your teeth for your news" and whose weapon of choice was a wagon wheel

A bogus gasman, here to ransack yer hoose.

The story of Tanis as told by Nick Silver and the basis of the Blair Witch Project. Both supernatural prescence or reality breach in the woods.