Classification: carnivorous necro-anthropomorphic aberrants.
Colloquial name: ghouls.
Origins: the first ghouls appeared in the Arabian Peninsula, before the rise of Islam. Much like therianthropes, ghouls can turn humans (baseline, magical, psychic) into more of them through bites, scratches and the exchange of fluids or tissues. Unlike weres, ghouls can be made "automatically". Dying while unprepared to depart and hungry can cause a human to rise again as a ghoul, if their animus has not already been claimed by the deity they worship.
Description: ghouls appear largely human, though paler, their skin being milky to grey depending on hiw dark it was in life, like in the case of vampires. Also like their undead cousins, ghouls possess sharklike fangs. Their organs do not function and their eyes are completely, milky white. Their nails can become clawlike at will.
Ghouls are carnivorous and constantly hungry, this need to feed varying in intensity depending on how often and much they eat (a mouthful of flesh us enough to render it negligible for minutes). Upon consuming flesh, the matter is instantly converted into energy, which is absorbed by the ghoul's body, resulting in dramatic increases in strength and durability (consuming the average man, for example, will result in a ghoul hitting like one and a half gigatons of TNT), and somewhat less impressive but notable increases in speed (a mouthful of flesh lets ghouls move too fast to be perceived by those equal to them before feeding). This ability is even more pronounced in the case of ghouls who consume paranormal flesh. For example, the smalles part of a vampire body will make a ghoul as powerful, fast and tough as said vampire upon consumption.
Behaviour: early ghouls' tendencies to steal coins, drink blood, eat corpses and hunt the young, elderly and infirm did not make them popular among humans, but this behaviour is widely-agreed to have been the result of particular ghouls' personalities, largely unchanged since undeath, rather than anything instinctive. Nevertheless, "ghoulish" became synonymous with "gruesome" after humans came in contact with them. Aside from their constant hunger, ghouls are not psychologically-different from humans to any serious degree (a far more laidback attitude when it comes to cannibalism is an arguable divergence, but this is considered synonymous with ghoul hunger, as they are not particular towards any species, including their own).
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Threat level: local (ghouls that have not fed yet); variable depending on the quantity and nature of flesh consumed. Ghouls are capable of withstanding tank shells with nothing more than bruises that heal within milliseconds; it takes tens of megajoules to give one a black eye. They are capable of hurting each other to the degree baseline humans can hurt each other, drawing blood and breaking bone. Ghouls are capable of easily reacting to attacks moving at (and fighting at) hypersonic speeds, up to Mach 12, running fast enough to melt granite, and will regenerate from any damage not inflicted by holy means, including quantum destruction or removal from the timeline. They are immune to direct esoteric effects and do not need rest, air or (other than psychologically) sustenance. Ghouls also possess limited shapeshifting, being capable of assuming the form of a hyena, or that of the latest person whose flesh they have eaten (abilities cannot be replicated, barring a handful of fringe cases). Ghouls have enhanced senses, equivalent to those of vampires, strigoi, weres and most Terran paranormals. When focused on spotting details, they are capable of distinguishing the individual hairs of a fly over twenty kilometres away, hearing its heartbeat and smelling its blood.
Neutralisation: other than borrowing blessed items or the services of faithcrafters (it is likely the pantheons would take exception to the Collective imitating their abilities through quantum entanglement or similar means) to deal permanent damage to ghouls, constant destruction areas should be set up. Restraints capable of withstanding hundreds of megajoules should be enough to contain fledgling ghouls, though materials capable of withstanding gigatons of energy would be necessary for any ghoul who has consumed even a few dozen kilograms of flesh (muscle, fat and bone fall in this category, though hair and blood do not; a quirk of aberrancy, doubtlessly).