Hellhound

A hellhound (pl. hellhounds) is a demonic dog that effectively acts as a bounty hunter for Hell. Like demons, they were once human, and either sold their soul or performed enough evil in life to be sentenced to Hell. Those souls who were especially effective hunters in life, or exhibited particularly canine traits, sometimes make the bargain to become a hound and hunt down souls in order for the chance to get out of the Pit. The longer they've spent in Hell, the less of their humanity remains.


Physiology

Hellhounds are not lapdogs - to those who can see them, they are massive black mastiffs, with an ominous, almost oily sheen to their coats. This form is invisible to those who cannot see spirits, with the exception of the soul they are hunting. Their teeth and claws are long and sharp, and in addition are capable of rending just about anything, whether corporeal or incorporeal. Their eyes are a glowing red, somewhat like embers, with no variation between pupil, iris, and sclera. Hellhounds can also adopt a human form that resembles their form in life, while not in Hell - in fact this is the only way for them to appear visibly outside of the Pit. Also, they are physically capable of overpowering any human.

To put it simply, iron burns. Any sort of anti-hellspawn weapon will likely be made of iron (and blessed for good measure). Holy water burns a hellhound like acid, though they heal these burns quickly, and it usually just pisses them off. Most hellhounds won't cross through running holy water if they can help it though. Demon hunters often spike their drinks with this, as an easy way to tell if one of their guests is possessed. Humans don't notice it any more than regular water.


Magical Characteristics

Hellhounds essentially have expired soul radar - once a contract is up, any hellhound in the vicinity (usually those working for the contract holder) typically reacts like a shark smelling blood in the water. When they attack, they first maul the physical body, and then drag the soul off to Hell. Even before the contract is up, a hellhound can sense souls, and 'smell' them in a way - they can tell if there is a contract pending on a soul, and how much karmic smut the soul is carrying around. The closer a soul is to expiring, the more tantalizing a soul smells.

Putting a pure iron collar or chain on a hellhound, in addition to pissing them off and causing them pain, gives you control over them, to some extent. They must do your bidding (within reason - you can't order them to destroy themselves, but you can order them to fight off other hellhounds coming to get you). Once they get that collar off, however, you'll be first on their 'rip apart as painfully as possible' list.

There are many ways to get into Hell - and far fewer ways to get OUT. Hellhounds can usually get out legitimately due to the nature of their work, but they are sometimes tossed back into the Pit for a bit of 'obedience school', so to speak, which makes escape more difficult. They cannot possess a human body. Once out of Hell, hellhounds can teleport from place to place (usually using crossroads) even between worlds - they cannot, however, use this method to get out of Hell, only to get to and from the corporeal side of the gates.

There are large sigils called Devil's Traps, generally involving a pentagram inscribed within a circle along with other symbols. Drawn, painted, carved, or inlaid on the ground or ceiling, they are effective traps for most hellspawn. Once they cross into the circle, they can't leave it again - unless the sigil is damaged and a line is broken. Hellhounds who notice the sigil before walking into one usually break it themselves, if they can (if it's inlaid iron, the best they can do is avoid it). Demon hunters typically put these up all over their homes.

An unbroken line of salt placed over a threshold prevents hellspawn from entering - alternately, they cannot cross into a circle made from it. Similarly, hellspawn (particularly hellhounds) cannot abide the plant known as Devil's Shoestring (a common name for members of the genus Viburnum, which comes from their long and flexible roots). The plants are used for protection, placed over windows and doorways to prevent hellspawn from entering. Holy symbols can also be used to repel most hellspawn - however, this is ONLY true if the wielder of the symbol has true faith in it, AND the hellspawn has no legitimate claim. In that case, the hellspawn cannot touch the wielder of the symbol, or directly do them harm (i.e. fling a bookcase at them). Hellspawn are unholy and cannot abide by holiness - however, if the wielder is corrupted, the symbol loses power. A Faustian contract also negates the effect - if you've sold your soul to the Devil, no divine power will protect you.


Society and Habitat

Hellhounds are among Hell's grunt workers. They can usually collect overdue souls for crossroads demons, though any demon with enough clout can bargain with a tormented soul to turn them into a hound. Demons typically treat them like pets… and demons aren't going to be winning any SPCA awards any time soon. In consequence, hellhounds are often not overly fond of demons - or anyone, really.