Physical characteristics vary, but they are commonly black, anomalously overgrown, supernaturally strong, and often have red eyes or are accompanied by flames.

[7] On mainland Normandy, the Rongeur d'Os wanders the streets of Bayeux on winter nights as a phantom dog, gnawing on bones and dragging chains along with it.

[8] In Lower Brittany, there are stories of a ghost ship crewed by the souls of criminals with hellhounds set to guard them and inflict on them a thousand tortures.

[10] In Greek mythology, Cerberus, often referred to as the hound of Hades, is a multi-headed dog that guards the gates of the Underworld to prevent the dead from leaving.

He was the offspring of the monsters Echidna and Typhon and was usually described as having three heads, a serpent for a tail, and snakes protruding from multiple parts of his body.

[12] In Catalan myth, Dip is an evil, black, hairy hound, an emissary of the Devil, who sucks people's blood.

In Galicia, the Urco was a giant black hound that led the Santa Compaña, a version of the Wild Hunt.

In the religious beliefs of the Guanche people of the Canary Islands, the Tibicenas were the canine offspring or attendants of the malevolent volcano deity Guayota.

They were associated with a form of the Wild Hunt, presided over by Gwynn ap Nudd (rather than Arawn, king of Annwn in the First Branch of the Mabinogi).

The dog is said to haunt the Hanging Hills, a series of rock ridges and gorges that serve as a popular recreation area and can also be known as a protector of the supernatural.

"[19] Additionally, the term is common in American blues music, such as in Robert Johnson's 1937 song, "Hellhound on My Trail".

The negative depiction of dogs likely derives from their close association with "eating the dead,' or relishing bones and digging out graves.

In the Dungeons & Dragons fantasy roleplaying game, the hell hound is a hyena-like creature that can breathe fire and hunts in packs.

[35] A hellhound resembles a mangy, skinny, somewhat demonic hyena-like creature with red eyes and draconic ears.

Nessian warhounds are coal-black mastiffs the size of draft horses and are often fitted with shirts of infernal chainmail.

The hellhound was ranked ninth among the ten best low-level monsters by the authors of Dungeons & Dragons For Dummies.