Ghouls are a carnivorous and cannibalistic species that are only able to feed on humans and other ghouls (the exception being coffee). Ghouls are similar to humans in both physical appearance and intelligence.
Because of their diet, ghouls are shunned and hunted by human society, making the humans hated by ghouls, though there are some ghouls who desire to live a peaceful life and instead exclusively eat the flesh of already dead humans instead of hunting them. Some ghouls even fell in love with and married a human, though ghoul-human offspring usually ends up being still-born, with only a few rare exceptions.
Ghouls have a high physical capability and are four to seven times stronger than the average human. They are able to send the average human flying if struck with enough force and can penetrate a human's body with their bare hands. They are also capable of jumping to heights not achievable by a regular human. Their bodies are extremely resistant to injury. For example, if a ghoul were to be stabbed with a knife, the blade would break instead, suffering a small scratch that heals almost instantly. However, higher kinetic forces, such as a fall from a great height, can and will harm them. Ghouls also have a higher sense of smell and hearing than humans to the point where they are able to tell different humans and ghouls apart by smell alone.
Despite their superhuman features, their most iconic trait is their kaguna, a predatory organ and functions as their weapon and claws. It is usually as red as blood, flexible like the flow of water, but firm and sturdy. When released, a ghoul's physique is strengthened, they are more resilient, and their mobility heightens. The CCG (Commission of Counter Ghoul) has identified four different kagune: ukaku a wing like kagune that is able to send out spike like projectiles, koukaku a blade like kagune, tentacle-like rinkaku, and tail like bikaku. In rare cases, the offspring of two different types of kaguna users can develop a hyrbid of his/her parents called a chimaera. When having cannibalized enough ghouls, a ghoul can develop a kakuja, a kagune that covers the entire body.
Battle vs. Vampires (by Appelmonkey)