On Halloween, you will likely see your share of run-of-the-mill monster costumes — vampires, werewolves, zombies, and the like.
While these creatures can no doubt be frightening, there are some lesser-known mythical and supernatural monsters from around the world that are truly the stuff of nightmares.
1. Acheri
Origin: Hindu & Native American Chippewa
The acheri appears both in Hindu folklore as well as a myth among the Chippewa people of North America. It’s a mountain-dwelling spirit created when a little girl dies a tragic death.
Using its shape-shifting ability, an acheri usually appears as a pale and frail young girl to befriend other children. Once it casts its shadow over a child, the child will fall ill from a deadly respiratory disease.

Acheris feed off misery and heartache and become more powerful as more children and people get sick.
To hear an acheri sing is considered a bad omen as their voices signal impending death.
Legend says that you can protect yourself from acheris by wearing red ribbons or a thread around the neck.
2. Baba Yaga
Origin: Eastern Slavic
Baba Yaga is an evil witch, legends of which are known in Eastern Slavic countries.
In many of the tales, she flies on a mortar instead of a broom. She also wields a pestle and eats children.

Many children in Russia are warned that the Baba Yaga will come and terrorize them at night if they behave badly.
In Poland, Baba Jaga or Muma is a monster that kidnaps spoiled children and eats them. There’s even a children’s game of the same name.
In yet other tales, she is known as a forest spirit who offers helpful guidance to those who respectfully seek her help.
3. Grootslang (Grote Slang)
Origin: South African
Grootslang or Grote Slang is Afrikaans and Dutch for “big snake.”
According to a South African legend, the Grootslang was one of the first creatures the gods ever created.
Bigger than an elephant and smarter than any man, the Grootstalng was a powerful and formidable creature.
The gods, new to the art of creating life, felt that they’d made a mistake by giving so much power to one creature.

They tried to correct their mistake by spreading the powers of the Grootslang across two animals: the elephant and the snake.
But one of the creatures managed to escape and kept this species of mythical giant snakes from disappearing from the earth.
Today, it is said that the Groostlang is hiding in a deep cave in Richtersveld, South Africa, waiting for anyone foolish enough to step foot into its dominion.
4. The Nykur
Origin: Icelandic
The Nykur is a shapeshifting, malicious spirit in Iceland.
They present themselves as friendly horses, but anyone who mounts them will be unable to dismount, as if held to the back of the creature by glue.
Then the nykur trots into the river or sea, taking the rider with it and drowning them in the process.

There are other similar water-horse creatures across northern Europe.
It is known as the nixe in Germany, the nøkk in Sweden, and the Kelpie in Scotland.
The story remains the same, though: it is a water-horse creature that hangs out near bodies of water and drowns anyone who dares to mount them.
5. Kumiho
Origin: Korean
Kumiho is a Korean mythical demon fox-woman with nine tails and shapeshifting powers.
According to Korean legend, the kumiho is a man-eater with a voracious sexual appetite. It often appears as a beautiful woman to seduce men and then eat their liver or heart.
If a Kumiho isn’t able to seduce and kill a living person, it’s said that it wanders cemeteries to dig out fresh corpses.

Additionally, a Kumiho can also use a magical marble in their mouths to absorb people’s vital energy through kissing.
While the Korean Kumiho shares some similarities to the Chinese huli jing and the Japanese kitsune, it is almost always considered malign and demonic.
6. Amarok (Amaroq)
Origin: Inuit
An Amarok is a fantastical giant wolf that roams the barren lands of the Arctic.
Unlike wolves who hunt in packs, the Amarok is said to hunt alone and devour any person foolish enough to go out hunting alone during the night.

Danish author and geologist Dr. Hinrich Johannes Rink recounted several tales regarding the Amarok in his book Tales and Traditions of the Eskimo.
He also pointed out that native Greelanders believed the Amarok to be a gigantic, “fabulous” monster. Other Arctic inhabitants used the term Amarok refer to any wolf.
I’m not going to lie; I really regret putting together this post at night. I’m going to have to sleep with the lights on tonight while holding tightly onto my cats.
Happy Halloween!