Hellhounds

On my way home from Oxfordshire, the mists closed in around our coach. I could barely see out the window and my coachman drove the animals slowly. I was thinking that we might want to pull off at the next inn to continue the next day when a baleful howl penetrated the fog. I peered through the window with my heart in my throat. There, in the distance, I spotted a pair of red points of light bounding through the mist. I could vaguely discern the shape of a dog running overland, its eyes glowing fiery red. Seconds later, the mist closed in and I lost sight of it.

— Lady Margaret of Darby, Anglia, 1704

Title page from an account of an alleged sighting
of a hellhound in eastern Anglia, 1577

Stories of hellhounds, black dogs, grims, and many more names are found all across the world. The stories differ, but there is always a dog and always an association with death. Alzamatrists that specialize in studying the etheric realm have proposed that the dogs are similar to soul guides in their make-up.
They seem to be able to appear and disappear at will, just as soul guides do, and Sighted people are able to see them even when they've vanished to most people. This leads to the belief that, like soul guides, they are able to phase in or out of the etheric realm at will.
The exact nature of the dogs isn't as clearly understood. Most stories of them agree that they are malevolent, and many mythologies assign them to gods or goddesses of the underworld.
Christian tradition describes them as creatures from hell that have slipped back out through the gates to the afterlife and stalk the land, but local traditions ascribe more folkloric origins. In the Prettanik Isles, they are usually associated with faeries.
What everyone agrees upon is that the dogs are malevolent. They are sometimes seen as an omen of impending death, but diviners claim they have no bearing on a viewer's death.
The majority of sightings claim the dog was on their way somewhere or else sniffing around, searching. Rather than fearing for your life upon seeing one, diviners claim you ought to be concerned for whomever the dog is searching.

Local Iterations

Black Shuck, Barghest, Gytruck, Moddy Dhoo, Cŵn Annwn

There are all names used throughout the Prettanik Isles to describe black dogs. Local details vary, but they are generally seen as omens of death.

Höllenhund

In Almain-speaking lands, the devil himself is said to take the form of a large black dog and roam the countryside. Seeing him in this form is very bad luck.

Chien Noir

In 9th century France, a black dog allegedly materialized in the middle of a church and padded down the aisle, as if looking for someone. Similar sightings have been recorded since.

Bulgae

In Chosun, dog-like beasts from the kingdom of darkness chase the sun and cause eclipses. If you run into one on a lonely road at night, it will bite a chunk out of you, too.

The Jackals of Anubis

Egyptian carvings portray black jackals, sent by Anubis to chase down the souls of the dead who fear Osiris' judgement.

Tlilitzcuintl

In Nahuac , a ferocious black wolf allegedly mauled a general to death hours after a miraculous victory in battle. The dog vanished like smoke when his outraged soldiers attempted to slay it.