One-eyed Ghoul

A **one-eyed ghoul** (隻眼の喰種, *sekigan no gūru*), also called **half-ghoul** (半喰種, *han-gūru*) is a human-ghoul hybrid who possesses a ghoul's abilities. Most ghouls treat their existence as an urban legend or have never heard of their existence at all.

## Characteristics

One-eyed ghouls earn their name from the single kakugan they possess, in contrast to normal ghouls. In all other ways, they appear to have no obvious differences from an ordinary ghoul. Some individuals are noted to have a unique scent that combines traits of a human and a ghoul, identifying them as different and often considered "enticing" by certain ghouls. Kaneki Ken has been shown to smell like a ghoul by some individuals whereas some cannot tell the difference, and Eto has been shown to smell like a human so far. It is unknown whether all hybrids have this trait. Their flesh and blood is also noted to be particularly delicious, making them a potential target for cannibalism. Dr.Shiba claims that the more half-ghouls and Quinx get hurt, the more their basic abilities will increase.

Rumours state that hybrids are more powerful than ordinary ghouls due to hybrid vigor, though it has not been further elaborated on. All specimens (except Furuta and Nashiro) have demonstrated radical evolution of their abilities and developed into, sometimes partial, kakujas within a short period of time. Physically, their bodies are identical to that of a ghoul with the same resistance to harm and ability to use a kagune. Artificial **one-eyed ghouls** can only consume flesh of human or ghoul origin like normal ghouls and thus they are strictly a cannibalistic organism. Natural one-eyed ghouls like Eto are able to taste and consume human food without negative effects. Hybrids come into existence through two methods, either normally born as a result of the union between a ghoul and a human, or through transplanting a kakuhou into a human host.

## Origins

### Pregnancy

Naturally-born hybrids born with ghoul abilities are extremely rare. According to Itori, the chance of pregnancy is low, and even if the mother becomes pregnant, the child normally dies during pregnancy.

* If the mother is a human and the father a ghoul, the child will not receive the necessary nutrients and will starve to death unless the mother engages in cannibalism. This only applies if every hybrid child resulted in a one-eyed ghoul, which, according to Arima, the chances are far too low. Indicating Itori is possibly unaware of the existence of half-humans.
* If the mother is a ghoul and the father is a human, the mother's body will mistake the child for food and absorb it as nutrition unless the mother weakens her body by consuming human food.

### Kakuhou Transplant

The primary method of creating one-eyed ghouls is through transplanting a kakuhou into a human recipient, an exceptionally high-risk procedure. In the rare event that the operation is successful, the human patient develops into an artificial hybrid with all the abilities of a normal ghoul. This procedure was pioneered by Dr. Akihiro Kanou, with the first successful patient believed to be Kaneki Ken.

Kanou, while experimenting with Takizawa, compared his surgery with grafting, a horticultural technique where the tissue of two trees are combined to help them both grow stronger. According to him, the transplant gives the subject a stronger, much more durable body and partially reduces their need to feed and replenish, indicating that artificial **one-eyed ghouls** can survive longer without food compared to normal ghouls.
Although artificial **eye-only ghouls** can live longer than humans and the Human Middle they must intake more RC cells because if they do not feed for too long, their lifespan will be slightly "shortened" and if the afflicted individual continues to use the [Kagune|[kagune]] their situation could worsen. There are two solutions to slow this aging and to regain strength: the first is to not use the kagune and the second is to practice cannibalism by eating other ghouls.

## Similar Variants

### Half-humans

Should a child be conceived from a ghoul father and a human mother, there are mostly likely to be born as half-humans and are far more common. They possess enhanced physical abilities but not the traits from their partial ghoul descent (i.e, lacking of kagune, kakugan).

### Quinx

Main article: Quinx
After examining Dr. Kanou's surgery on Ken Kaneki, the CCG created an experimental squad consisting of humans with ghoul capabilities through implementing a kakuhou covered by quinque steel layers. While the Quinx are not considered as normal half-ghouls due to their lower Rc cell levels and the ability to eat human food, they are made from the concepts of Dr. Kanou's half-ghoul experiments.

### Oggai

Oggai are stated to be made differently from the QS in a new and innovative process. They were created under the authority of newly-appointed bureau director Kichimura Washuu using Akihiro Kanou's perfected kakuhou transplant surgery. As a new race of one-eyed ghouls Oggai have the previously unheard of ability to choose either to activate one or two kakugan at once. It is estimated nearly a hundred individuals were produced, each enhanced to be superior trackers and adept ghoul exterminators. Kichimura compares them to Ken Kaneki, the original prototype on which they are all based.

### Modified Humans

So called "Modified Humans" are distorted failed experiments of Kanou that did not quite exactly become One-Eyed Ghouls (hence their need to use weapons like Quinques at times) like Taro. They tend to be intellectually disabled, massive in size, and muscularly deformed. The majority of the failed experiments that fall into this category were given to Madame A as pets/her "children" or scrappers.