Larva

Larvae, also called soul larvae, were what remained of the souls of mortals corrupted by evil that were unclaimed by fiends via contract or otherwise. They were trapped in the Shadowfell or Hades to be captured by predators such as night hags, rakshasas or liches in order to be consumed or sold.

Living mortals could also be transformed into larvae by prolonged exposure to the plane of Hades.

Description
Soul larvae were long, yellow, worm-like monsters whose squirming bodies appeared both sickly and fat. They oozed an odorous, viscous slime from their bodies that coated the ground they wriggled across like a slug's trail, producing a noise like a vomiting dog as they moved. The actual body of a soul larva was fluid, almost liquid in texture, and the foul stench of their sticky secretions never seemed to fade. Rather than the head of a worm, soul larva had a much more disturbing feature, a grotesquely deformed head with facial features reminiscent of their former mortal form.

Behavior
Soul larvae were wretched, miserable creatures stripped of the intelligence and personality they had in life apart from faint, leftover recollections. Despite their greatly reduced mental faculties they could still understand the languages they knew in life, and scholars that studied them believed them to possess their own crude and indecipherable language of instinctual body motions.

Those in the Gray Wastes were generally lacking in ambition, typically lying down in the emotionless wasteland in massive piles, barely moving, if not at all, unless provoked somehow. In their practically motionless hordes, some occasionally wormed their way to the top while others sank to the bottom, sometimes biting each other or those bothering them. Larvae from other planes were known to struggle more in an effort to survive, such as ones from the Shadowfell that attempted to escape.

Abilities
Although pitifully weak, the fangs of soul larvae were still dangerous and caused those bitten by them to bleed profusely. They also harbored a deadly, degenerative disease that could result in painful skin rotting for those bitten. Three weeks into the illness, a victim would need to lie completely still to avoid further health risks but death would still come after a month with only cure disease magic as a viable cure.

Combat
Only when compelled to by a more powerful entity would the larva of the Gray Wastes swarm their assigned foes. Otherwise, they generally left others alone even when a mortal was in their midst, although it was possible to drown in a sea of the wriggling worms when they were packed closely enough together, an experience that often proved extremely traumatizing.

Society
Soul larvae lacked any kind of society or culture of their own and to most were mere horror stories used to scare children straight, but were immeasurably important to those of the Lower planes. Larvae were the epitome of untapped, evil potential, able to serve a myriad of purposes throughout the evil-aligned planes. In terms of economy, soul larvae were a form of basic currency for night hags, evil deities, liches, devils, daemons and demons. They were worth approximately 1,000 gold in the Abyss, although its denizens rarely used material payment. They could be used as food, especially for entities that required life forces to survive such as liches, or as a kind of base "soulstuff" for dark rites requiring esoteric components.

Most importantly, soul larvae were a foundation for several populations in the Lower planes, and given the incalculable amount of fiendish life lost in the Blood War every day, a number that only ever seemed to increase, such creatures were extremely useful for restocking armies. Soul larvae, as the tabula rasa of the Lower Planes, could be used to create new fiends by devils and demons as needed. To some, all larvae were equally pathetic and so their selection was randomized, while others were more discerning. Once transformed, they were just as likely to reach the pinnacles of their respective societies as any other member, but the number of larvae that rose past the lowest rung was abysmally low, much less the number that managed to become true fiends at all. It was claimed that larvae that showed particular promise were allowed to skip the unthinking castes of demon and devil society and immediately become lesser members. Larvae were the primary, if not, the only way to create quasits and imps, which harvested souls from mortals to further increase fiendish populations, thus allowing them themselves to advance, making them crucial to Lower planar ecology.

Ascension
The weakest of mortal incarnations within the Abyss were soul larvae, that barely survived in its infinitely hostile lands. Demons had learned ages ago during the Blood War how to shunt most soul larvae to the Woeful Escarand on the 400th layer of the Abyss, allowing the nalfeshnees known as the lords of woe to promote larvae as they saw fit. The pompous nalfeshnees promoted almost all souls that they didn't use as food, turning the inept into manes, the sufficiently malevolent into dretches and the reciprocally arrogant into rutterkin. The nalfeshnees' guidelines served more as vague suggestions than iron rules that they would likely ignore at a whim, arbitrarily deciding what to do with larvae as they came. Their claims of astute judgement were in all likelihood false and the chaotic system mostly farcical as some nalfeshnees were known to willfully promote weak larvae or take other steps to embarrass their balor masters.

Unlike the whimsically capricious choices of the demons, devils allowed the harsh and unwavering process of natural selection to weed out all but the most durable and determined of soul larvae, removing favoritism or subjectivity from the equation. Only the best larvae of Baator, about one out of every couple thousand, were molded into the amorphous lemures, one of the ultimate examples of baatezu imposing their form of law over others. Soul larva seen as unfit were used for one of their plethora of other purposes or transformed into gaunt reflections of their former selves after being purchased in the markets of Dis, forced to serve as the walking damned in a tormented form for an intended eternity.

The larva trade was focused in Hades due to the fact that the souls their were as equally accepting as law as they were chaos, allowing the hags to contend with both sides equally. Baatorian larvae were too immutable in mindset, fixated on their form of order and often times difficult to adapt to the baatezu version of lawful evil. Abyssal larvae on the other hand were equally stubborn for the opposite reason, many times proving too malleable and unstable to keep their tanar'ric forms for long before returning to their larval state and merging with the Abyss. Although each side would hate to admit it, the baatezu loathed to be reliant on others and the tanar'ri claiming they only participated to counter the baatezu, it was ultimately easier for both the larvae of purer evil quality from Hades, ensuring the profit of the night hags.

Trade
Night hags had long since monopolized the soul larvae trade, having learned how to quickly discern larva quality with unrivaled efficiency. While the best larvae were sold at a premium, the worst were culled, sometimes eaten by the hag herself, or sold at discount to those that didn't know better. It was possible to haggle the price of a larva with their hag owner depending on how much she needed the money and they were willing to trade in gold, magical items, information, favors or even the customer's own soul. They were gathered by the hags and their servitors in great herds, with branding irons used to mark and move the vermin along as they followed slime trails to find more of them. Larvae were used by the night hags as leverage, traded with powerful fiends for freedom on the lower planes and with liches in return for the destruction of their enemies, often potential customers that refused to trade.

The larvae trade was both complex and constantly expanding due to the continuous increase in planar inhabitants and was centralized in a particular spot in the Gray Wastes. Few hags chose to covey, but the largest and longest-lasting was the Grand Larva Emporium of Oinos. Whether demon or devil, all fiends came to the Emporium for its fine quality larvae to the point where it could be unquestionably called the commercial center of the Lower Planes. The massive bazaar operated on an ideal spot next to the River Styx where merrenoloths ferried passengers by the hundreds for a day's worth of shopping and yugoloth mercenaries, as equally well-armed as they were paid, executed any that attempted to disrupt trade. Entire larvae herds were brought in by night hags that rented a spot from the covey that owned the Emporium and an equally vast variety of clients disputed prices and carefully examined potential purchases.

Uses
Larva byproducts could be found in a wide range of lower planar merchandise like the distilled larva liquor known as "Yellow Wurm Stout" or a female-marketed perfume called "Evil", many of which could be found in the Emporium.

Rituals
A great proportion of larvae were used to power wicked spells and heinous rituals by entities such as night hags, liches and rakshasas, their life essence used as an energy source. The recipe for creating an altraloth for example, required a huge cauldron of Styx water and larvae to be sealed from wax made of their slime residue. At the end of the process, the larvae fully dissolved and their essence was consumed to complete the metamorphosis resulting in an explosion of caustic larval fluid and the emergence of the new being. Night hags also required a hundred soul larvae and a month's time to craft a new heartstone if their old one was destroyed or made irretrievable.

Consumption
Larva were just as likely to be used for magical purposes as they were to be consumed, resulting in the permanent, absolute obliteration of the soul's existence and the shriveled husk disintegrating. Demons were among the most well-known for their consumption of soul larva and did so as a method to gain power within the Abyss. Some did so immediately upon finding them while others hoarded them in order to feast in times of need and undergo a dramatic power increase. Demonic overlords often demanded that their minions bring regular tribute in the form of soul larva in a form of protection racket yet others still willingly offered the soul larvae to their lords to curry favor with them. Destroying even a damned soul was seen as distasteful at best and utterly revolting at worst to most non-evil beings and doing so could have adverse effects for some beings. Other fiends also consumed soul larvae energy, as did some liches in order to sustain their undead bodies.