Demon

Demons were the most widespread type of fiends. They were chaotic evil by nature, and were native to the Abyss. Demons had no true rulers, though powerful demon lords and deities were able to gain enough power and influence to gain control over sizable armies of demonic creatures. They were also the sworn enemies of the devils, though their ageless Blood War came to a cool upon Asmodeus' ascendance to godhood.

Subcategories of demons
There were three main subcategories of demons, widely known and distinguished between among scholars and sages.

Obyriths
The oldest of the demonic races, obyriths were ancient creatures of chaos and insanity said to have come from an entirely different reality. They ruled the Abyss for eons and were responsible for creating the tanar'ri, before an ill-fated war broke their armies and a subsequent slave revolt drove most of them into hiding or to extinction.

Tanar'ri
The most numerous of the demonic races and the rulers of the Abyss in the modern times. The tanar'ri were born spontaneously of the Abyss, although some bore signs of being altered by sibriexes or other creatures. Tanar'ri occurred when evil mortal souls enter the Abyss; the first tanar'ri was Demogorgon.

Loumara
Loumara demons were the youngest demonic race, consisting of immaterial beings that possessed people, creatures, or objects to spread evil. They were theorized to be born from the dreams of dead gods killed by the Abyss.

Other demons
Not all demons belonged to one of the three main subcategories of demons. These other demons were divided by the Demonomicon of Iggwilv into three other groups. Demonic creatures created by some powerful entity, such as a demon lord or, more rarely, some other powerful entity like a night hag or very powerful mortal spellcaster. These creatures were made either from other demons or from the raw material of the Abyss itself, but were not spontaneously created by the Abyss. Interestingly, Iggwilv included quasits in the created category, despite the fact that they were known to spontaneously arise from the Abyss. She also theorized that in time various Created demons would be "accepted" by the Abyss and begin to spontaneously arise as well. Created demons could be undead, constructs, or even truly living outsiders.
 * The Created:

Undead demons:
 * Blood fiends, huge, four-armed creatures that fed on the blood of other demons.
 * Haures, bizarre demons created by Orcus.

Demonic constructs:
 * Retriever, mindless, spider-like constructs that were created to serve stronger demons of the Abyss.

Living creations:


 * Bonegouge assassins, stealthy creatures said to be created by Orcus.
 * Ghazneth, humanoid, winged demons with differing magical abilities.
 * Ghour, demons that took the appearance of monstrous minotaurs, ghour demons served (and were likely created by) the demon prince Baphomet.
 * Ferroliths, demons created from succubi that had been thrown into molten iron by Graz'zt.
 * Quasit, the demonic equivalent of the imp, were small, insidious winged demons with paralyzing claws.
 * Shoosuva, large, hyena-like demons that were created by and served the demon lord Yeenoghu.
 * Tomb demon

Some creatures produced by the Abyss acted like what would, in saner places, be called wildlife. They were generally unintelligent.
 * Beasts:
 * Abyssal chickens, small creatures that did not actually resemble chickens.
 * Kazrith, aquatic demons that poisoned their prey.
 * Maw demons, also called Abyssal maws, were horrible looking, constantly hungry demons.
 * Nashrous, animalistic predators that hunted in packs.
 * Skulvyn, bestial aquatic demons with a slowing aura.

Similar to the Created, servitor demons were the least populous group. They were created by deities as servants, proxies, and agents. Some servitor races were abandoned to the Abyss when their creator moved on or died.
 * Servitors:
 * Deathdrinkers, egocentric demons that collected dead souls.
 * Yochlol, shapechanging demons that were created by and served Lolth.
 * Zovvut, winged demons that had outlived their creator.

Even with the six categories described by Iggwilv, many demons defied categorization, either due to lack of sufficient knowledge or the sheer chaos of the Abyss itself.
 * Other demons:
 * Abyssal wurms, two-headed, many-legged demons.
 * Bebelith, massive, highly aggressive spider-like demons.
 * Demon spawn
 * Immolith
 * Jarrlak
 * Mahataa
 * Quarrak
 * Rageborn
 * Shadow demon, mysterious demons with a wraith-like appearance.
 * Voracalith
 * Whisper demons, incorporeal demons of insanity that drove mortals to suicide.

Demon Lords
Demon lords, or Abyssal lords, were powerful demons that commanded many other demons and ruled a layer of the Abyss. Each demon lord had a unique appearance and set of abilities. The most powerful demons lords were called demon princes. Since demons had no set hierarchy, both titles were self-proclaimed, and the demon lords and princes fought against each other constantly. Demon lords were also considered archfiends.

Connections
Dämonen