Necrilum (Neck-rill-um)

Summary

The Necrilum are a hivemind race of undead beings with a singular purpose: wipe out all sentient life on the planet. Where they came from is unknown, but all evidence points to these creatures being the reason that the Progenitors were wiped off the planet. Necrilum reproduce by bringing corpses back to their hives, where the biological material is then processed into a new Necrilum. A hive is a living being, and slowly spread out over the walls, floors, and ceilings of wherever they form. All hives have a central core, which needs to be destroyed if one wants to get rid of the infestation. A hive without a core will begin to shrivel up and die. Hives begin to form wherever the Necrilum begin to gather.
There are three tiers of hives in Necrilum infestations: nests, hives, and necropolises. Nests can pop up at a moments notice and are the juvenile form of a hive, but they are relatively easy to clear out as nests are unable to produce new Necrilum yet. A hive is a more matured version of a nest and are able to produce new Necrilum, albeit slowly. These start to become more difficult to root out, as they're often at least room-sized and well-guarded, making it more difficult to pinpoint where the core is. There have only been a handful of necropolises in Haven Alpha, and only two have ever been fully rooted out. The others are under constant watch to try to cull any expansion efforts the hive may make. It is considered to be a suicide mission to try to remove a necropolis, and it's generally advised to just prevent them from forming in the first place. A Necropolis can output a steady stream of Necrilum, and often form sub-cores to help prevent the death of the hive. If all sub-cores are not eliminated before the main core, one of the sub-cores will grow to become the main core and take over the hive.

Phenotypes

Necrilum all belong to a hivemind, yet it appears as though there are two competing hiveminds within Haven Alpha that seem to have to very different ideologies when it comes to the future of the Necrilum species. The first and most common of the Necrilum are organics, where the hivemind has decided that rapid evolution is the most efficient path for their continued existence. The second and rarer of the two are cybernetics. The hivemind behind the cybernetic Necrilum has opted to fit all it's Necrilum with a wide variety of cybernetic augmentations designed to aid them in their tasks. There is one final kind of Necrilum as well, however, and it is the most concerning of them all: sentients.
There are three different kinds of Necrilum, and it appears as though there are two different, competing hiveminds trying to control the Necrilum. The two hiveminds are organic Necrilum and cybernetic Necrilum. The last kind is the most concerning of the lot: sentient Necrilum.
Organic Necrilum exhibit mutations that allow them to execute their intended purpose more efficiently. For instance an organic meant to chase down and incapacitate a person might be quadrupedal and have muscular jaws that are hard to pry off of one's limbs, or a Necrilum meant to break down the walls of a settlement for an attack might tower over any average person and have one massive, club-like arm meant for smashing. Some organics bear some semblance of the creatures they once were, but many have been twisted completely to better suit their new purpose.
Cybernetic Necrilum are the rarer of the two primary types, and feature a wide variety of cybernetic implants; some look more machine than monster. Most of these Necrilum have very simple yet function augmentations, but some have cutting-edge technology embedded in their bodies. The hives of cybernetic Necrilum often look more like a nightmarish production line, and the sheer amount of space required for them to produce and implant their cybernetics mean that cybernetic hives are quite rare, yet considerably more well-defended than an organic hive of comparable size. People rarely try installing Necrilum augmentations for fear of what it could do to them, though some do find their way onto the black market.
Sentient Necrilum are often a terrifying foe. These beings have broken free from their hivemind, and are often above average in intelligence when compared to the average person. It's unknown what causes a sentient to form, but it's theorized that it's actually a flaw in their reproduction process. Often times a sentient will continue serving their hivemind on their own terms, and will use their new critical thinking skills to act as effective leaders for their hive, but on rare occasion a sentient Necrilum will actually strike off to live it's own life. These renegades often still have the urge to hunt down sentient life, yet not all have this murderous impulse. While usually not welcome to live within settlements, some sentients prefer to study and understand the lifeforms they've been instructed to hunt. Some manage to live relatively ordinary lives, while most like this end up becoming scavengers and mercenaries taking on contracts to seek out a living.

Organic Necrilum

These creatures adapt through rapid evolution to overcome any obstacles in their path.

Cybernetic Necrilum

Steel is stronger than flesh, and it serves the Necrilum well.