Kos (Mother) is a non-player character in Bloodborne. This page is theoretical lore with musings by fans, and not to be taken as official or canon.


Kos (Mother) is a giant, sea-dwelling Great One whose dead body gives birth to the boss, Orphan of Kos. Her corpse, which according to Kos Parasite is teeming with alien parasites, washes up on the shores of Fishing Hamlet.


Micolash, Host of the Nightmare:
"Ahh, Kos, or some say Kosm... Do you hear our prayers?"
"As you once did for the vacuous Rom, grant us eyes, grant us eyes. Plant eyes on our brains, to cleanse our beastly idiocy."

Kos Parasite
"When the carcass of Kos washed up on the coast, its insides were teeming with tiny parasites, unlike any found in humans.
This atypical weapon can only be clasped tight and swung, but a Kos Parasite is said to stimulate phantasms inhabiting a lumenwood"

Fishing Hamlet Priest wishes the "wrath of mother Kos" upon the blood crazed fiends of Byrgenwerth.

A latin translation of the ambient music of Hypgean Gaol suggests that they are addressing Kos, the "sleeping slug".
This song is called "Hail the Nightmare".

1. Is Kos a Great One? (by Rakuyo)

Many Snail Women can be found praying in the cove near her corpse, suggesting that she is adored and worshipped by the local cult.

It is stated that all Great Ones lose their child and instead yearn for a substitute. The orphan may be such a substitute for the great Kos. Some believe Kos that she somehow ingested the orphan to turn him into something else, much like the Moon Presence embraces and alters Hunters. If she is a Great One then she seems to be one that is bound to the "bottomless ocean" of the Fishing Hamlet realm. Seeing as one can see Yharnam from the waters of this nightmare realm it is possible that these waters are connected to the sky above Yharnam.

(note: There exists a theory that worlds in Bloodborne are layered. Such layers are modelled after Norse mythology where Midgard (middle-earth) forms the center between a world of gods above (Asgard) and a hellish world (or worlds) beneath. In Norse mythology this is made possible by the great ashen tree Yggdrasil which holds up the nine worlds. In Dark Souls there are giant (ashen) Archtrees which are so tall they seem to hold up the sky. In Bloodborne one can spot nigh identical structures by peering around in the Hunter's Dream.)

Careful examination of Kos' carcass reveals very human arms and hands, as well as a seemingly perfect human face. While not enough is known about the Great Ones to state that they cannot resemble humans, it does seem strange to find one that could pass for a large pale woman. Her alien features on the other hand, bear many resemblances to the Crawlers found in the Nightmare Frontier as well as those of the Snail Women found in Fishing Hamlet. Careful examination of Snail Women reveals that they have shiny, fishlike scales, just like Kos. Crawlers share her pale skin and alien appendages. When Crawlers use their poison attacks, it is revealed that they have dead babies inside of them. (As it turns out these babies are "living", blackened messengers). Summarized, she looks like a giant Snail Woman swallowed by a giant Crawler.

Kos being a Great One would explain the attention of Byrgenwerth. Her corpse and orphan may have provided most of the blood that launched Yharnam's "Old Blood" enterprise. The strange link between the waters of Fishing Hamlet and the sky of Yharnam suggest that she lives above Yharnam, watching the goings-ons of its people. There's still plenty of mystery concerning her death and the significance of her orphan. The Moon Presence is intimately linked to the rise of Byrgenwerth, this could mean that Kos and the Moon Presence were enemies but much is left to speculation.

2. Is Kos the reincarnation of Quelaan? (by Rakuyo)

Quelaan is a friendly NPC in Dark Souls and leader of the Chaos Servant covenant. She is colored brightly white and is half human, half mutant spider. She is addressed by her servant Eingyi as "the fair lady". Quelaan is in a sorry state, she took pity on the denizens of Blighttown and sought to cure them of their misery by absorbing the poison in their bodies. Did Kos try and do the same? Did she seek to cure Orphan of Kos' "curse" and die in the process? As it happens, Kos has inexplicable insect legs sticking up from her abdomen, much like those of a dead spider.

A quick google search reveals that Kos is a Greek island known for having housed an advanced society. Kos was admired throughout the Hellenistic world for its extraordinary Asklepieion (a healing complex). This facility was founded by no other than Hippocrates of Kos. This connection to healing does fit the parallel between Kos and Quelaan. If Kos was a healer, she may have had a benevolent nature as well.


3. Is Kos the Aztec goddess Chalchiuhtlicue? - by Rakuyo

Chalchiuhtlicue was the Aztec goddess of water, rivers, seas, streams, storms, and baptism.

She was a patron of childbirth and a ruler goddess who once transformed her own people into fish

She is associated with sea serpents and seashells. She is married to Tlaloc Tlaloc god of rain. She also has a son - Tecciztecatl. 

Tecciztecatl was known as "the old man in the moon" and he's often pictured carrying a large, white seashell, representing the moon.

Tecciztecatl is also called "he who comes from the land of the sea-slug shell." 


According to Aztec mythology, the world has been created five times. Four worlds have been destroyed by the gods and we live in the fifth world.

The first world was created by Tezcatlipoca "god of night" - the second by Quetzalcoatl  "god of wind" - the third by Tlaloc "god of rain".

For the duration of his reign, each god served as the Sun of that world. Chalchiuhtlicue was to be the fourth Sun.

Her male predecessors had each grown angry with the world's people and they had each destroyed the world's people.

Chalchiuhtlicue presented a welcome change. She was kind to the people.

She also built a bridge linking heaven and earth and those who were in Chalchiuhtlicue's good graces were allowed to traverse it.

But Tezcatlipoca "god of night" would bring the fourth world to an end. 

He convinced Chalchiuhtlicue that her kindness was dishonest and that she was only pursuing selfish needs.

This upset Chalchiuhtlicue so that she cried blood for 52 years.

The resulting floods destroyed the world, but Chalchiuhtlicue turned people into fish so that they would survive.

There are two main myths as to who became the fifth Sun. In one it is the war god Huitzilopochtli, in the other it is the fire god Nanahuatzin.


Kos is a giant mermaid or sea serpent or slea slug. Chalchiuhtlicue is a lady of water associated with sea serpents, she's also connected to shells.

The Aztecs considered Chalchiuhtlicue's son - "The Old Man in the Moon" - and The Orphan is an old man carrying a moon shaped placenta.

Fishing Hamlet is generally considered to be located in the past. This fits the idea that Fishing Hamlet represents the fourth world destroyed by water.

Chalchiuhtlicue is a patron of childbirth, children, midwives and goddess of baptism. This can be tied to the unusual birth of The Orphan of Kos.

Below are words spoken during an aztec baptism.


"Behold this element without whose assistance no mortal being can survive. Receive this celestial water that washes impurity from your heart. 

Son receive this divine water, which must be drank that all may live that it may wash you and wash away all your misfortunes,

part of the life since the beginning of the world: this water in truth has a unique power to oppose misfortune. In which part of you is unhappiness hidden?

Leave this child, today, he is born again in the healthful waters in which he has been bathed, as mandated by the will of the god of the sea Chalchiutlicue."


Fishing Hamlet as Tlalocan

Tlalocan is one of the 13 Aztec heavens. It is ruled over by Chalchiuhtlicue and her spouse Tlaloc, god of rain.

Tlalocan harbors those dead that died by drowning, lightning strikes and those that died physically deformed.

Aside from being fishmen, the inhabitants of Fishing Hamlet tend to be hunchbacks and their priests cast bolts of lightning.

The realms also accepts those that died of diseases related to water. This could be read as "diseases related to blood".

Tlalocan is also home to Acihuat. This "lady of the waters" is thought to be the same as the Mexican Llorona.

La Llorona is a ghost of Mexican Folklore, a kind of female bogeyman that drowns children.

Llorana means "weeping woman" and is said to dwell near places of water. Her cries cause misfortune to those who hear it.

She is bound to this world because of her terrible crime. To exact revenge on her husband, she drowned her own children.

At night she wanders around, looking for children that resemble her own. She drowns them, hoping to regain her children.

It isn't known if this ghost is an actual character in Bloodborne or merely used for inspiration.

According to the Aztec story, Chalchiuhtlicue-Kos did in fact drown her children with her tears, but there's no corpses near Kos.

The Snail Women on the other hand appear sorrowful and they do moan. It wouldn't surprise if they tried to drown anyone.

4. Possible Theory on Kos and Orphan; SPECULATION SUPREME (sorry for essay) (by Fiddlesticks)

A lot of this isnt actually written, its more of observation, and it does get weird, but it is sort of possible, I believe. Lets start! What killed Kos? we dont have much to go around with, but we do have some evidences. First the wrecks, masts of sunken ships surround the boss fight area. The fishmen tend to use harpoons a lot, which is overkill for fish. I believe the fishing hamlet would hunt whales as well, a whaling town. They could had found and attacked Kos, threatened by her massive alien form, or thinking she was a strange whale swimming in the sea. Many ships were sunk, but eventually Kos died.

We know that Kos was teeming with alien parasites, Kos parasite info. We also see many little blue worms or slugs on corpses, as well as the strange slugs the fishmen store as food. I think that upon her death, many of these parasites left her body and mutated the village into fishmen, turning them into kin. News of this lead to the scholars of byrgenwerth raiding the hamlet and, according to the accursed brew, searching for eyes in the skulls of the mutant Kin fishmen. This act suggests they are Kin, as Kin of the Cosmos are the elevated humans, closer to great ones but not ascended enough. Master Willem does mention that in order to ascend, we must line our brains with eyes. Landing visceral hits on fishmen also leads to a lot of serum-ish Kin blood flowing from them. Its not the usual red.

Back to Kos, we have another clue on her death, its how the Orphan exits her body. If you look at the flesh where he leaves, and where he ends up, staring at the moon, you can infer that the orphan came from her side. This part lacks evidence as we cant really tell how the anatomy of Kos is, what if thats normal for her type? But in the case that it isnt, what if the Orphans strange exit meant that there was a gaping hole in the stomach of Kos? Exposing all her guts and womb, which is how her umbilical cord was taken? We know from the note three third cords...the scholars know of the power of great one cords. There is no way they would leave treasure like that alone. Kos is dead but seems unhurt with no visible cuts or anything. However, if we flip her over, that maybe a different story. The way her stomach flesh ends is also different from her tail, its so thick and bulbous at the end. It doesnt look natural and it could be from a wound.

Unfortunately all this has many holes OTL, for example, whaling Kos. Kos would be absolutely loaded with harpoon cuts on her back...but I have a counter for this! Its that Kos can fly! My proof is the Orphan, her not fully developed son sprouts wings in his second form. I bet with more development and practice, he could fly. Cant be sure, but if this is the case, Kos takes it to the sky after being attacked, and most of her wounds are at her stomach. Well its all speculation but lets not forget the Orphans lightning power. Most likely Kos has it too, and if she did that in the water, she will hit herself. We also know that the Orphan is not immune to lightning, though he is resistant. I believe it was a power meant to be unleashed as you fly or on dry land.

Next issue, Kos has a very human face, and human hands, could she had once been human, or some church experiment? Maybe, the only counter I have for this chance is the alien parasites in her. Where would those come from? And if she were an experiment, then she needs cleaner, sanitized conditions as her body would be vulnerable during the transition. The presence of alien parasites suggests she wasnt conditioned for things like that, however, the theory that she was once human still has footing. What if she got the parasites after transforming? She fled and lived in some alien place, though how she would find her way to alien parasites holds question. Its also possible that inserting alien parasites found in chalice dungeons was the experiment performed on her, which explains the parasites. However, if that was the case, why dont we see more like her? A result that good, very alien, yet with human features...why is this not replicated or improved? After all, the events of the DLC seem to have occurred a long time ago. I think that she just so happened to be a human like great one, or maybe she was once a human who became a kin, then hundreds or thousands of years later, she ascends from Kin to great one.

Oh, god, this feels like an essay bit, if Kos was attacked by the people of the Hamlet, why do they seem to worship her? Shouldn't they hate her? Well people back then were a superstitious lot. If they witness what they assumed as an ungodly monster suddenly unleashing arcane power, lightning for example, they could think" Oh no, its no devil we angered but a god!". Lets not forget the possibility that the parasites from Kos could had changed the people. Well it could also had been powerful great one magic too, like a curse. Anyway, this change will strengthen the "We made a mistake" thought of the people. A godly punishment for angering a higher being. They worship the carcass as seen by snail women who pray to her. Maybe they hope she would turn them back, however this bit, doesnt have solid footing. If they pray to her, in hopes of returning to humans, then they should also act that way, and not be uncivilized man eaters who live in ruins. Perhaps in awe or fear of her as a great one, they worship her.

Psycho Orphan bit...even less footing here... Ok, lets start with the snail women! They worship Kos fervently, but something is off. Why dont they approach her or shower her with gifts? Many praying ones cant even see her body. That is because of fear. Not of Kos, but of the Orphan. Now this bit gets weird, but bear with me. "Mercy for the wizened child". Wizened means dry, shriveled and wrinkly. Usually by age. We all know that this is in the past, Kos didnt die yesterday, or last year, or a decade ago, she has been dead for a long time. Just look at the wrecked hamlet that used to be civilized, barnacles everywhere, old rotting wood. Lets not forget Ludwig who who, according to Yharnamite hunting clothes, recruited citizens for the hunt a long time ago. This was when there were actually people to recruit. Now they are practically all crazed beasts. Eileen the crow, who used to dream, seems to have hunted and fought until she became an old woman. I am suggesting that the Orphan has been around for a long time, he was not just birthed right when we approached him.

He heard or sensed our approach and exited his mother. It is too much of a coincidence that he is birthed right when we approach and that mom is dead. The snail women avoid the area, because moment a thing gets close, he exits and if it still approaches, he crushes and maybe eats it. The orphan sleeps there. This wizened/ old child, is not a baby. Maybe it takes a hundred years for a great one to grow up, we dont know, but this is not a newborn baby. It is a child. Look at Ariannas new born. A legit baby. The orphan doesnt even face his mom when he comes out. He knows she is dead, long ago. Look at how affectionately the tiny baby of Arianna stares at her. Its an obvious weak newborn baby, but not this Orphan.

The wizened child, might only be a child by behaviour or state of mind, always crying over his mother and never leaving her side. How long has he been here? Note that we hear him crying before he comes out. He isnt drowning in fluids, he can open his mouth and cry. He has serious issues, misses his Mom so much, he went insane, harboring this nightmare. He probably hoped to renter his mothers womb after he kills us and his tantrum ends, except he never kills us because we keep coming back. I know it sounds crazy, but think about it. The first thing this new born baby does to the first man or woman he sees, is approach slowly, walking, not crawling, then run at full speed and leap, trying to crack their skulls open with his weapon. That is no newborn, he has killed and maybe eaten other unwelcome visitors before. The snail women pray, but they dont want to pray too near. They hide in a cave, away from his sight or hearing. They know what awaits them if they approach.

I get that this is wild, The Orphan has a placenta attached to him, sign of a baby, but what if that is his only reminder of his mother left? He refuses to totally consume it and evolve. You have to force him to consume part of it, and he instantly gets bigger and grows wings. I bet if he gorged on the whole thing he would be as big as Kos, but he wont because its his reminder of her. But wouldnt it have rotted away if he was that old? Well the body of Kos isnt rotting. The dream may preserve this or make it immortal. It could also regenerate. I mean it looks alive, and all. What if it could restore itself, but an act like eating it permanently drains it?

Like I said, lots of holes here like the connection to Gehrman being an old man, and the Orphan looking old and the potential scythe like form of his placenta. For me, I dont find the placenta very scythe ish, its more like a club or sword, a chain sword then.As for the connection to Gehrman...well the first hunter could had participated in the raid of the village. I dont have much to go around here, but maybe the Orphan felt a bond between the fish people and him. He hated the hunters for the raid. But the fish people seem to fear him but in a god way...may not have been that close. They dont send guards near him... We know that the Orphan has a black ghost that truly holds the nightmare. We also know that Gehrman, the first hunter, could had lead the raid, as he was the first and probably best hunter at the time. What if Gehrman found the corpse of Kos, cut the belly open and killed the Orphan, took the cord too. The orphan having died in the real world can only sustain himself by nightmare. He unleashes his curse and the nightmare and is reborn. He creates a new form for himself in the nightmare, but all is not well. He is miserable and misses his mom greatly. He cant move on and refuses to develop, ages as a child, becoming a wizened child. Note that you no longer see the Organ he came out of ( very heavy speculation here) it just vanishes. I think he tucks or nudges it back in with his feet. To keep his mothers appearance up. He doesnt want to see Kos injured so she would appear alive, even though he knows she is dead. He probably flipped her over if her wounds were exposed so he would not see them. He could use her as a house or blanket, creepily crawling back into her womb to sleep or rest by entering the massive stomach cut. He is probably too big for the natural way. All this madness torments him until you end him as the hunter.

But the theory about the Orphan's form being after Gehrman isnt bad. Its a nightmare, and for the child of Kos, the baddest, scariest thing in his short life must have been the first hunter who could have opened his mom, took the cord and ended his life in the waking world. As for how Gehrman sleeps easier after killing the Orphans ghost...well i only have more loose speculation there. The Orphan wanted to trap him in the nightmare, but could not because he was already caught in the Hunters Dream. This child cannot match the fully developed Moon Presence. He only succeeds in a piece of Gehrman's soul, tormenting him at times through nightmares I guess. This ends my essay, sorry for long read. Remove if its too long haha...


This character can be found at The Coast, and any notes on any other encounters

    • Can this NPC be an ally?: No
    • Can this NPC be an enemy?: No




Other Notes:

  1. One may assume that Kos was cursed and sick and that this caused her death. The description of the Kos Parasite states that she was teeming with alien parasites. The skin of her belly looks heavily inflamed and has a putrid color. When Orphan of Kos is born, the placenta he drags behind him looks a great deal like a cursed blood gem.



Kos (Mother) Face 2.png

Kos (Mother) Hand.png

    • 18 Mar 2017 14:04  

      some parts of what you say deserve many congratulations and the part of the child who is old in reality and uses its mom's body as a lair...well that's perfect, the same about the prayers who keep the distance. The orphan surely is born much time ago and can not separate from her mom. I think Kos was a loving mom, and not bad as the others great ones. Even her aspect is too different from the other great beings. I am also sure the population tried to kill her, and she broke the ships. The old fish-man says "for the wrath of mother Kos", so the population of the village has witnessed her rage, probably because they attacked her, and killing her could mean killing her beloved son. Probably it was she who transformed the population in fish-men, probably because her nature is not a killing nature (as a great being she could kill everyone in the village).Then the hunters came to the village to study the population, they may have taken some of them to do horrible experiments, indeed we know the experiments of the church had the aim of creating great beings artificially (bosses Living Failures), and probably Kos defended the now fish-men population, becoming then worshipped. The population knows how evil is the orphan, the old fish-man says to "forgive" the orphan. Since it is the son of the loving Kos, and since it passed through a tragedy, the population somehow "forgive" him, but never approaches him. He is still an evil being. The circle is closed ^^

      • lore?05 Jul 2016 08:48  

        She should be an inhabitant of the hamlet but was impregnated by an unknown-not-yet-appear-before great one for a surrogate child (which is the last boss). That act turned her into the monster we saw and that somehow affects and transformed all the females in the hamlet into something like her, hence the snail ladies...

        • Quelaan05 Jul 2016 08:48  

          That theory is so dumb I cannot express it in words. <br/>One similarity in roles does not suggest reincarnation. If it did, then we are in fact playing Dark Souls 3.

          • Fisherman deity05 Jul 2016 08:48  

            A youtube user pointed out that Kos might have been a deity worshipped by the fishermen, and when the college hunters attacked, they killed Kos. As a result, the villagers or the orphan cursed the hunters to be forever trapped in the Hunter's Nightmare. Her death was a tragedy to the fishermen, and was probably done by Gehrman and Maria, hence their guilt.

            • Relation to Rom05 Jul 2016 08:48  

              Micholas speaks like Rom was a person transformed into a Great One (or Kin) by Kos, and that Micholas wishes to receive this gift as well.

              • Heavy editing needed05 Jul 2016 08:48  

                Kos Parasite outright states that the corpse that washed up on the beach was in fact Kos, and most of the games dialogue and descriptions relating to her can lead one to safely assume she's probably a great one, though what this means in regards to her ability to give birth seems to be unkown. Also, Kos being a reincarnation of Quelaan? There's nothing wrong with wild-mass-guessing, but an official page on a wiki that people access for reliable and probable information is no place to throw up conjecture that is more than likely wrong, or at least highly fanciful. Please try to adhere to a certain standard here.

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