Chasme

A chasme was a type of tanar'ri demon found in the Abyss.

Description
Frightful, wretched, and disgusting in appearance, a chasme resembled a terrible demonic cross between human and fly. With the body of a giant fly, it bore large, buzzing wings and carried six limbs, the two forelimbs resembling long, slender human arms with long-fingered hands. It had a head vaguely like that of a human, but ugly and exaggerated, with tiny mouths and a large horn-like nose. This nose was hard, sharp, hooked, and could bite and suck blood. Tufts of wiry hair sprouted from between the black plates that covered its thick, insectoid body. The chasme could walk upright or crawl upon walls and ceilings as they willed, and of course fly with excellent maneuverability.

A chasme could grow to between 7 feet (2.1 meters) and 9 feet (2.7 meters) in length. However, as suited a flying creature, they were very light, weighing a mere 150 pounds (6 kilograms).

When speaking, chasme had a rasping, buzzing voice, but typically preferred to communicate via telepathy.

Ecology
An adult chasme could spawn up to ten young each year, via pre-fertilized eggs that it laid in the rotting corpses of enormous demons or other creatures. These eggs hatched after three months, and hatchlings grew to adulthood in seven years, though they could lay their own eggs after two.

Chasmes were carnivorous, preferring to drain a sleeping victim's blood via their horn-like proboscises.

Although they could operate over any kind of land or underground, chasmes favored lairs against vertical surfaces with many ledges to roost upon. These included cliff-face rookeries, vast caverns, and treetops. They were common in the Abyss, and especially prevalent on the layers of the Crushing Plain and Torremor, once home of Pazuzu, the demon lord of all evil things that flew.

Preferring the company of their own kind to other demons, chasmes often gathered into gangs of around three to ten members.

Activities
Left to their own devices, gangs of chasmes flew over the layers of Abyss, endlessly hunting for things to torture and torment, hopefully things weaker than themselves.

They would set aside their hatred of other demons for the chance to serve greater demons, even demon lords, as interrogators, taskmasters, or torturers. In this role, they kept slaves and lesser demons repressed and obedient through the application of punishment and intimidation, which they greatly enjoyed. Thus, chasmes sometimes acquired positions of influence and power in the Abyss.

Chasmes had a particular knack for spotting demons that had fled their masters or deserted the Blood War. It was unknown exactly how they did this; some speculated they had a psychic ability to sense the thoughts and emotions of tanar'ri, perhaps even other, non-tanar'ri. Chasmes went to great lengths to recapture runaway demons and bring them back to their masters, so that they might receive a reward and the opportunity to further torture the wretch. They also roamed the layers of the Abyss, hunting for Blood War deserters, and punishing them with a slow and agonizing demise. For this service, they avoided front-line duties in combat formations, and their places were filled by other tanar'ri, which earned no love for the chasmes.

In a few cases, chasmes claimed some small pocket of land on the Abyss or another plane and set themselves up as petty demon princes in miniature. These princelings ruled over minor demons like dretches and rutterkins.

Relations
Chasmes bitterly hated most other demons. They did not like vrocks, viewing them as rivals. They nursed a traditional hatred of succubi, and would kill them given the chance. More powerful demons, like glabrezu and hezrous, they feared and obeyed. Lesser demons, like dretches and rutterkins, they ruled over if they had the opportunity.

Chasmes were in turn utterly detested by other tanar'ri, thanks to their role in recruiting for the Blood War while avoiding it themselves. As a result, tanar'ri often attacked chasmes on sight, with only the chasmes own strength and the support of the demons they served protecting them.

Possessions
Although they carried no treasure, and bore no weapons or armor, chasme occasionally made use of magical items that they came across. They also enjoyed delicate artworks studded with gemstones.

Uses
The wings of chasmes were sometimes harvested for use in potions of flying.