Black Dogs - United Kingdom
The legends of black dogs go back hundreds of years. The concept is simply, really - a large black dog haunts the victim for days or weeks before a misfortune or death occurs. Black dogs are like harbingers of personal disaster, like a banshee, and are almost universally described as evil. Physically, they are obviously entirely black, save for glowing eyes, and are often significantly larger than a normal dog. Primarily nocturnal, sightings over the years report them appearing night after night and then disappearing after the target died or suffered a loss.
There are many legends out of England that speak of black dogs haunting castles, moors, and ancient roadways, prowling in the shadows and then disappearing or sinking into the earth. One story that's particularly famous is the legend of the squire, Richard Cabell. There are various accounts of what happened in his life, but one thing is certain; he was an evil man. The tales vary, one suggesting he was an intensely violent man who murdered his wife, and was then killed in turn by her black dog. Another tale suggests he was an excellent huntsman who sold his soul to the devil, and upon his death, black dogs were seen circling his tomb, ready to claim his soul. The legends report that to this day, he can be seen on the Dartmoor in Devon, England, with his pack of black dogs, haunting the countryside. Always seen at a distance, the hunter and dogs speed through the wilderness and vanish before they can be approached.
Another story centers around Newgate prison in London (which was torn down in 1904). A man was sent to stand trial for witchcraft, but was brutally murdered and eaten by the starved and mistreated populace. Shortly after his death, a monstrous, black hound appeared, terrorizing the inmates. They killed the guards and fled the prison, but the legends say the black dog tracked and killed every one of them, who all died raving about being hunted by a huge, bestial dog that only they could see. From the time of the death of the man to the dissolution and demolition of the prison - 400 years - the dog reportedly appeared on the grounds of Newgate before every single execution.
Mongolian Death Worm - Mongolia
Walk in the Gobi desert in Mongolia long enough, and you may come across a Mongolian Death Worm. Said to be about 2 to 4 feet long, this red worm travels underneath the sand, looking for its primary prey; camels. Though it hibernates most of the year, it becomes active between June and July. The danger of the worm comes in two forms - it spits an acid capable of corroding anything (and killing a human on the spot) and it can discharge a pulse of electricity strong enough to kill a person. Tales have been passed down regarding the worm for generations within the Mongolian people, but the worm received more wide-spread notoriety because of a 1926 book by Roy Chapman Andrews "On the Trail of Ancient Man". He spoke with the Prime Minister of Mongolia, who explained the beast lived in the far reaches of the Gobi desert and was extremely poisonous. Andrews did not believe the man or the other elders of the village, as none had ever seen the creature with their own eyes, but noted that they all very much believed it existed.
In terms of terror, it would be difficult to beat a creature that travels underground and can kill you at a distance. Though there have been expeditions to find the creature since the early 1980s, nothing has been found. That said, if a creature like this was going to hide itself, what better place to do it than a huge, expansive desert, waiting to catch an unwary traveler by themselves?
Cait Sidhe - Scotland
The cait sidhe was a fairy creature, described as a very large black cat with a single spot of white on its chest. Said to be the size of a large dog, the cat itself wasn't necessarily antagonistic or evil. Some legends speak that the cat was actually a witch able to transform into a cat at will, and having this ability 8 times in her life, the 9th transformation leaving her as a cat forever. The size and markings of the cat set her apart as a supernatural entity, and this is regarded as a basis for the idea of "cats having 9 lives".
The common folk of Scotland were not at ease with the idea of the cait sidhe, believing that the creature could steal the soul of a buried person who had not yet passed to the afterlife. The cat did this by simply stepping over the graves of the newly-dead, and so Scottish families designated people to prevent the cait sidhe from doing just this. Interestingly enough, the legends say the cat could be kept from stealing a soul by playing with it, offering catnip or music, or wrestling with the beast. These people had to do this in total darkness as well, for no fires could be lit - the warmth from the fire would attract the cait sidhe surely as anything. Though not as scary as the other creatures on this list, it would still be unnerving to come across a dog-sized house cat in the middle of the Scottish moors late at night!
Akerbeltz - Basque Region
The akerbeltz has an interesting history. For the Basque people, it represented a being that brought fortune to those who believed in it and treated billy-goats favorably. The creature was a sort of priest for different types of land fairies, elves, lamia, or other supernatural creatures, and in modern times, it's seen as a protector of animals. In his role as protector, the akerbeltz can use powerful magic to defend animals and the very land in which it lives from human elements.
The akerbeltz is described in different ways, but the primary features are those of a goat, with huge horns, black fur, and human facial features. It lived literally inside the land, able to pass through solid objects like a ghost, but had a true physical form.
The bulk of the descriptions of the akerbeltz come, not from the Basque people, but from Christian inquisitors and missionaries who were looking for witches to persecute. The stories all negatively describe the creature as a goat-headed demon, or (incorrectly) as a huge dog or steer. The stories also describe the creature performing mockeries of Christian rituals and baptizing witches in service of the Devil. Most of the Basque stories don't actually have anything negative to say about the akerbeltz, save that the magic he uses to protect animals can cause huge variations in weather patterns, from torrential rains to hail. The Basque people highly regard billy-goats because of the akerbeltz, particularly black ones - it's seen as good luck to have one in your house!
Kamaitachi - Japan
The "sickle weasel" is a pretty peculiar creature. The legend goes that these spirits ride on dust devils, spinning so fast that they cut humans without causing pain. Often, the movements of the weasel are so hypnotic that the person doesn't even know they're cut until after the creature has passed.
Various stories depict the creature as a natural phenomena, when an unexplained injury occurs, or the work of an evil god or sorcerer, who uses the spinning chaos of the dust devil or wind to hide a conjured spirit. The spirit would then do harm to the victim, and in return, the kamaitachi could drink the blood of the wounded. This is the explanation for the deep cuts but lack of bleeding.
Other stories depict the phenomena of phantom cuts being the work of the spirits of harvest sickles, left in a field and falling to disuse. Japanese spirits are often the angry ghosts of inanimate objects who seek revenge for one reason or another, and this is a common transformation of a lot of Japanese stories. The sickle weasel, however, is the much more widely spread version of the phenomena, and is even used to describe particularly fierce snowstorms in some regions of Japan.
Conversely, stories from the Edo period of Japan (1600s - late 1800s) state that, after a rainstorm, a kamaitachi would live in puddles. Those who splashed in or played in the water would receive the tell-tale cuts to their legs, because unless the creature is floating on a whirlwind or dust devil, it can only jump about 30 centimeters high. These legends, however, describe the cuts going from bloodless and painless to gushing and extremely painful later on in the day. Regardless of how you encountered the sickle weasel, it was not going to end well for you.
Though there are a lot of similar stories around the world about phantom animals, legendary monsters, and mythological creatures, cultures vary widely. Black dogs are definitely different in Japan than they are in England, and the beliefs surrounding cats vary from mischievous tricksters to deities, depending on where you're standing. Some people believe the above legends and myths are grounded in reality - that these creatures existed and possibly still exist today. Still others believe that they're nothing more than stories, often used to try and explain something that at the time, just didn't make sense. Regardless, at the time of this writing, Halloween is fast approaching, and the dark, cool nights with swirling leaves and earthen stillness give pause, making a person think twice about what they believe are just stories and what just might be real.