Loumara

The loumaras are a relatively new demonic race, much younger than the tanar'ri. They are still centuries old, but this is still recent in a place like the Abyss, where time doesn't mean the same thing it does on the Material Plane. As a result, few loumaras have yet become powerful enough to be recognized as demon lords; Sifkhu, who has been captured by the succubus queen Malcanthet, is perhaps the only one.

Loumaras are usually immaterial or invisible demons that are more like ghosts or undead than demons. Most of them possess living creatures or objects in order to more effectively work their evil.

The loumara race resulted from the Abyss's attempts to digest the dreams and memories of a pantheon of dead gods. This pantheon, a territorial bunch, was killed eons ago by the Abyss itself, when Demogorgon baited them into destroying the layer of one of his rivals; as the angry gods ripped an entire layer free from the Abyss, the Abyss lashed back, slaying them all so that only their thoughts remained. The Demonomicon of Iggwilv speculates that each breed of loumara evolved from the dreams of a different dead god, and that their natures are a corruption of that god's portfolio. The dybbuk is believed to have been born from the dreams or nightmares of a dead goddess of love and art, the guecubus from those of a god of law and peace, and the dreams of a goddess of nature and fertility formed the manitous.

Dybbuk
A Dybbuk resembles a jellyfish with a simply sketched human face. Dybbuks can possess and control dead bodies, so they spend a lot of time looking for a 'perfect' host body to animate – one that died without violence or major injury, and preferably one that is handsome or beautiful. After taking the control of a 'perfect' body, dybbuks try to insert themselves into the society of the victim, plunging into depravity and hedonism until their possessed body is broken down and ruined. When a 'perfect' body is not available, a dybbuk will take a less desirable body and continue to search for a better host. Dybbuks are lonely creatures, and can be found in groups only where there are many corpses to possess, such as on a recent battlefield. They tend to avoid undead, because already-animated bodies are of no use to them.

Guecubu
A Guecubu resembles a mass of vapor, and is born from dreamstuff tainted by evil. Guecubus can possess and control the body of sleeping humanoids. Once they are in control, they 'ride' silently, letting their victim go about his or her business. At some point they take control and lash out, trying to spread death and murder – particularly the victim's family and friends. Sometimes the guecubu will conceal its actions even from the victim, letting them believe that they are cursed or jinxed.

Guecubus believe that killings form some sort of pattern, and enough spilled blood will eventually reveal the meaning of creation in this pattern. They rarely form groups with other guecubus, preferring to remain hidden and anonymous. However, many of them can be found in the Dreaming Gulf (230th layer of the Abyss), where they are created spontaneously from the raw, churning chaos of dreams.

Caligrosto
Sadistic even by the standards of the other fiendish races, Caligrostos live within weapons, having a particular affinity for slashing weapons such as swords. A Calisgrsto's greatest desire is for the weapon it lives within to be carried into battle by an adventurer and allowed to inflict suffering; it will often enhance the weapon with magic properties, so that adventurers will be more inclined to wield it. When a Caligrosto's weapon inflicts damage on an opponent, the Caligrosto may tear the weapon from its master's grip and manifest on the battlefield, taking the form of a shade and mimicking whatever creature the weapon struck most recently. It will then proceed to slaughter whatever whatever it can find.

Manitou
A manitou manifests, in its true form, as a tangle of ghostly vines, each tipped with a fanged maw. Manitous can possess any animal, plant, or fey. In their incorporeal form, they can literally tear apart the natural world with the invisible forces at their command.