Ghouls

Ghouls are a relatively rare yet greatly feared species of the demihumans. Their millennia-long predations gave birth to numerous myths about cannibalistic abominations hiding amidst humans, waiting for them to lower their guard. This lasted for as long as to shape human's instictual reactions to threats, with ghouls and ghoul-like entities typically causing an instictual fight-or-flight reaction in onlookers.
They are nocturnal, solitary predators, noted for their superhuman strength, intellect and ability to masquerade themselves as humans. They might be way beneath the threat level of some of the more physically (or magically) impressive dangers out there, but underestimating them is an easy way to die.

Basic Information

Anatomy

Ghouls are former humans whose speciality lies in hiding among those of their old kind. As one can expect, their body is (outwardly) that of an unchanged homo sapiens. This is, naturally, only a mask that they don to hunt more successfully.
Their main physical difference from humans - if you exclude more supernatural alterations - is centred upon their jaw. It is optimized towards much more impressive bites - ones that shatter bones and tear flesh. It is equipped with both a greater bite strength and an assembly of fangs. Their mouth can also open wider (it's best described as someone's cheeks 'splitting open') to fit more of things inside.
Their baseline strength is also improved (enough for them to easily butcher non-Initiates in melee), together with their body's natural flexibility and movement speed. Their other notable abilities include generalized stealth (they can move almost soundlessly, especially at night) and a particular form of an inhuman scream that causes instinctive fear in humans when heard up close. it is normally used for intimidation and to break morale of the prey that has grouped up against them.

Biological Traits

Ghouls possess the natural ability to pretend to be human beings. However, one thing has to be said about it. It works much better during the day. Humans are, after all, diurnal creatures. Ghoul has to interact with their prey during the day when human eyesight works the best. During the night, those restrictions are much less limiting. Looking less human tends to be a good way of hiding their daylight identity from the prey that survived an attack.
Ghouls are thus a species of limited shapeshifters. They can shift their human hands into much stronger hands ending with razor-sharp claws. They can also shift their teeth from the normal human ones into a collection of fangs. Their cheeks can split open, making their smile inhumanly wide but also allowing them to fit bigger things into their mouth. They can prolong their tongues to get all the bone marrow out of the bones of their victims.
What's more, their posture when going 'full ghoul' is slightly changed as well, with prolonged (and strengthened) upper limbs. Their eyes are also animalistic, with vertical slits and a slight glow in the dark.
Their day and night forms aren't mutually exclusive. Ghoul cornered by the Initiates during the day CAN manifest their natural weapons. However, being human at night (and being ghoulish during the day) tires them quickly. Engaging identified ghouls during the day is a standard tactic, as their baseline physical strength and endurance are lowered by at least thirty per cent (more if ghoul is malnourished).

Genetics and Reproduction

Ghouls can reproduce, although it is a rare occurrence. They are, as stated, solitary predators, with their contacts with others of their kind typically resulting in a murder attempt to preserve their hunting ground. Sometimes, however, it does happen.
They are capable of procreating with others of their kind, normal humans and some of the other demihumans that haven't deviated too far from the human baseline. The species of the children will be ghouls - it's rather common for ghouls to manipulate non-Initiates into relationships, using their spouse to guard their child while hunting for food (the spouse typically becomes a victim as well, once the child is ready to go out to live on their own).
Prenatal ghouls lack teeth, but they still have their hunting instincts and a jaw with a lot of strength. Having a human woman carry a ghoul child to term is slightly more dangerous than normal (especially if she is malnourished, which often results in their ghoul child being hungry).
The length of pregnancy is identical to the normal one. There are cases of non-Initiate (or even Initiate) human women not realizing that their children aren't human until birth.

Ecology and Habitats

Ghouls (especially the first generation ones) are fully capable of pretending to be humans. Sometimes they pose as the mundanes, sometimes as solitary Initiates. They can have a normal job, have friends and so on, all to further improve their masquerade. After all, weird loners are easy to draw the attention of the Initiates.
They will typically target humans unconnected to them as prey, although this might change if they lose themselves to hunger. Modern transportation means makes eliminating them even more complicated, as they can easily hunt dozens of kilometres away from their home.

Dietary Needs and Habits

Ghouls can only satiate themselves on human blood and flesh. Eating anything else will make them violently ill (and they abhor the taste instinctively). Most find sustenance by hiding among the human population and assaulting their neighbours at night.
Normally, they need to kill at least a single human a month to remain sated. This makes them into solitary predators. Larger groups of ghouls will quickly run out of food or gather the attention of the Initiates.
They are, however, capable of going for an extended time without eating. It is a mechanism that allows ghouls to avoid overfeeding - and lets them lay low while their prey is on high alert. The longest time a ghoul can go without eating is approximately six months. However, staying hungry for so long carries the risk of ghouls going into a rage when exposed to fresh meat (for example, if someone is wounded in front of them).
Those that maintain some of their prior humanity can satiate themselves by sneaking into the morgues, digging out corpses or preying on other fallen and physical undead. They can eat creatures that used to be humans, although such meat tends to 'taste funny' and sometimes makes them ill.
They can also eat relatively small bits (for example, a mouthful a week), maintaining a low profile at the cost of being permanently hungry.

Additional Information

Perception and Sensory Capabilities

All ghouls come equipped with excellent night vision and a sense of smell to match it. They can sniff human blood in the air at a distance counted in hundreds of meters. At that distance, they can also tell if they already smelled the blood of that particular human being and even their general state (agitated, dying, afraid etc.). Their ability to detect and analyze non-human entities is notable lesser but still superhuman.

Civilization and Culture

History

Ghouls predate the establishment of human civilization. It is unknown how ancient humans managed to persevere despite their constant predations. Many scholars suspect that most ancient tribes and settlements were cultivated like livestock by their resident ghouls. This lasted until early Initiates managed to obtain enough knowledge and power to locate and eliminate their ghoulish overlords.
It is suspected that traditional ghoul traits (looking like humans but not entirely) are partially responsible for shaping human 'Uncanny Valley' reaction. The same can be said about human's instinctual fight or flight reaction towards humanoids with prolonged limbs and too wide mouths.
Today ghouls are suffering constant setbacks due to modern Initiate groups awareness of their hunting patterns and limited food supply. While human numbers grow steadily, finding their fresh corpses requires breaking into morgues or funeral houses. Something that immediately alerts any Initiate group in the area of the presence of ghouls. Normal hunting tends to alert them as well.
If they were a purely natural species, they would be driven to extinction by now. However, their numbers are regularly replenished by powerful Initiates falling to the malignant influences of the Ancient of Flesh. As a result, ghouls remain a permanent threat.

Ghoul

Summary

Type: Demihuman
Subtype: Ancientbound
Status: Kill-on-Sight [With Exceptions]
Estimated Numbers: 15 000- 40 000
Censor's Veil: Displayed as humans.

Alignment

Creator Power: Ancient of Flesh
Alignment Status: Varied
Sanity Damage: Immune [fear]
Corporeal Stability: Immune [physical harm]
Magic: Free fleshshaping [amplifies hunger]

Combat

Combat Behaviour: Ambush Predator/Impersonator
Threat Rating: 3
Physical Damage: Vulnerable
Magical Damage: Vulnerable
Glyphs: Immune to Wards
Notable Vulnerabilities: Daylight