Demons

This species of unknown name, being called Demons by the children, Man-Eaters by the unnamed man, Monsters by the Goldy Pond Resistance and simply as They by Sister Krone, are tall humanoids with monstrous appearance and the main antagonists of the series. They are the beings that command the "Demon World" in Factory Farming and Premium Farms.

History
It is currently unknown how the "demons" got to Earth or if they were native to Earth at all. Anything after the year 2015, which is stated by Ray to be the last year of any updated book at the Grace Field House.

According to Sung-Joo, "Demons" preyed on Humans in times of old, until some of the Humans started to fight back. After countless deaths and wars, a promise was formed between the "demons" and the Latley family. The human and demon realms were split in two, where neither was allowed to cross nor hunt each other. The Latley family left an unknown amount of humans in the demon realm, stranded with no way to escape, to become livestock to the demons in order to keep peace in the human world. Thus the plantation system was formed via a loophole, as the demons were not hunting them.

Types of Demons
All 5 known varieties of demons bear different and unique appearances to distinguish from one another.

Farm Demons
Farm Demons are all tall beings that have a long pointy face with two eyes above each other and two horns on top. They have a mouth with sharp canines and a long tongue. They have long arms, six fingers, and sharp nails. They each have four limbs and walk on two legs.

Some demons have been seen with a pipe connected to their mask. It is currently unknown what this is for. All demons so far have also been seen wearing a black cape.

Tamed Demons
There appeared to be demons which bears the most resemblance to the man-eaters (with the exception of having four instead of six legs instead).

Heathens
Heathens appeared to have the most human-like looks compared to the other varieties of demons— they each have four limbs and walk on two legs. The heathens are also the only group of demons to have horns on their heads.

Just like the farm demons, the heathens are polydactyly, with six fingers on each hand and wear masks which allow them to see through two holes positioned at the top and bottom.

Heathens are specifically known for their religious beliefs of not eating humans, but that does not restrain them for doing so in future, as a heathen, Sonju, bears the desire to prey on humans again in future.

Poachers
Poachers appear to be the wealthiest kind of Demons around. They look and behave the same as Heathens, with the exception of how they wear clothes which are more prestigious. These demons also wear masks to protects their eye from any harm. Poachers appear to have 3 long fingers on each hand, have tall slender bodies and quick reflexes. They also seem to be really fast, showing this with their exceptional abilities and skills.These Demons buy or steal humans from the Premium Farms and hunt them for fun and excitement. They hunt them in their secret hunting reserve called Goldy Pond. Aristocrat Bayon hunts for fun while Archduke Lewis is known for his hunting skills, who hunt for excitement. The demons eat human meat after each hunt, with the meat nicely chopped into pieces shaped like steak.

Wild Man-Eaters
Being the least human-like than their other counterparts, man-eaters crawl on six legs and have numerous eyes, and are completely unclothed. They also appear to be the largest of the species. a wild-demon can be killed quite easily if a human is an experienced demon-killer like Emma, Ray and Yuugo for example. Making this kind of demon weaker then their tamed counterparts.

Powers and Abilities
Anthropomorphism: For anthropomorphic demons, similar to humans, they can walk on two legs and speak human language. Several anthropomorphic demons are often seen equipped with weapons such as spears and daggers, which they use to hunt humans and even their own kind.

Language: Besides being able to speak the human language, the demons sometimes tend to communicate in their own native language.

Ear-piercing scream: A wild demon can let out an ear-piercing scream to signal to its surrounding allies.

Invulnerability: Wild demons are also shown to be rather invulnerable to physical attacks. This was shown when they were unaffected by Emma and Ray's attacks, like Emma's arrows and Ray's bullets. Unless they are aimed at their eyes, which is considered their weak spot. Similarly, during the fight Emma, Ray, Nigel and Violet had with Lewis, the team successfully shot and broke Lewis' mask, but the demon himself remained unhurt.

Regeneration: Demons can heal any kind of (their) wounds, except their middle eye.

Demon Eating: Can be eaten by other Demons, this results in the two minds of the demons merging, acting as one.

Enhanced Speed: Wild demons are known to be physically adept (and possibly more so than their civilized counterpart) as shown as they are capable of running, pouncing onto their prey, and climb up trees at great speed.

Enhanced Reflexes:

Weaknesses
Middle Eye: Currently, there is only one known weakness the demons have: Their middle eye. Figured out by Ray, anthropomorphic demons are always seen wearing masks which either partially cover up their faces (with two holes on the top and bottom which allow them to see)- they are used to protect the eye right in the middle, as it is known to be a demon's most vulnerable weak spot. Once the eye is destroyed, the demon would immediately die.

Diet
So far, the only thing known to be eaten by them, are humans from Premium Farms and Factory Farms. Though, a picture has shown that shows the demons surrounded by other foods like chicken, sausage, grapes, apples, bread, wine, and cats.

The Demons offer the premium-grade quality food to a certain demon they worship.

Trivia

 * Although they are referred to as demons by the orphans, there have been people who are denial to calling them demons. Whenever they say demon, the word is quoted or they call them by a different term:
 * Sister Krone's response to Emma and Norman: "The 'demons'? Oh, you mean them?"
 * Sonju, similar to Krone, stated: "The ancient contract between human beings and 'demons', sealed so long ago. We live in the half allotted to the 'demon' side back then."undefined
 * When a person on the human side made a proposal to cease the fights between humans and demons, he stated: "Human beings shan't hunt 'demons' anymore. In return, 'demons' shan't hunt humans either. This world we live in shall be divided between both."undefined
 * "Heathen" means someone who does not belong to a widely held religion as regarded by those who do. This might explain how heathens like Sonju and Mujika are only a minority out of the vast majority of demons that eat humans.
 * The wild demons/man-eaters are ranked 20th in the Popularity Poll that was announced in Chapter 88 of the Manga.