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These Giants may think they will rule. Let them be our shock troops and destroy the Olympians - all well and good. But once the Earth Mother is awake, she will remember that we are her eldest children. Mark my words. The Titans will yet rule the cosmos.

–Koios to Iapetus, in The House of Hades.

Koios (also known as Coeus) is a son of Ouranos and Gaea. He is the Titan of Farsight, Intellect, and Knowledge, and is also the Titan Lord of the North. His Roman form is Polus.


Early Life

Gaea, his mother.

Koios was the second son born to Gaea and Ouranos, the respective personifications of the earth and sky (after Oceanus). The Titans were the eldest of the three races born to Gaea the Earth and Ouranos the Sky, before the Hekatonkheires (Cottus, Gyges, and Briares) and the Elder Cyclopes (Arges, Brontes, and Steropes). All were detested by their father, but he detested the younger children so much (mainly for their ugliness) that he imprisoned them in the terrifying abyss of Tartarus, which was itself deep within the Earth. Enraged, Gaea told her remaining twelve children (including Koios), the Titans, to take the mighty Scythe that she had forged, and avenge their brothers by overthrowing their arrogant and sadistic father. However, while Koios detested his father, he was ambivalent at the prospect of murdering him and so were most of his other brothers and sisters, and did not step up to take the Scythe. However, after his younger brother Kronos did, Koios agreed to help him in the murder. Nonetheless, Koios' elder brother Oceanus, as well as his sisters Theia, Tethys, Themis, Phoebe, Mnemosyne, and Rhea all refused to participate, saying that they all had important things to attend to.

Murder of Ouranos

While preparing to ambush his father Ouranos, Koios hid himself in a deep pit, which he covered with leaves and twigs. Together with his brothers Iapetus, Krios, and Hyperion, Koios held Ouranos down, after which Kronos used the Scythe to slice Ouranos into a thousand pieces and claim his supremacy over the universe. However, right before Kronos sliced him up, Ouranos predicted that one day Kronos himself would suffer the same fate at the hands of his own child. After defeating his father, Koios roared with laughter, along with Hyperion, Krios, and Kronos. Afterwards, Kronos hurled all of the remaining pieces of Ouranos into the sea as a gesture of loathing against his brother Oceanus for not helping slay their father. Much later, these particles would mix with the ocean spray to form Aphrodite.

The Titan Lord of the North

After Kronos claimed his supremacy as the Titan King of Mount Othrys, and ushered in the "Golden Age", Koios was justly rewarded for his help with control over the North. Koios was one of Kronos' most loyal followers, held in great esteem by Kronos himself. Koios was also the only Elder Titan who was naturally clairvoyant, and could accurately predict the future. As a result, all of Koios' siblings, nephews and nieces would frequently approach him with questions about the future.

In time, Koios married his beautiful sister Phoebe (the Titaness of Mystery), and fathered three children with her: Leto (the Titaness Protector of the Young), Asteria (the Titaness of Prophetic Dreams), and Lelantos (the Titan of Air and Hunting Skills). Unfortunately, since Koios lived far up north, and Phoebe lived near the Oracle of Delphi, they could not see each other very often.

Shortly after the birth of his children, Koios no longer visited Kronos on Mount Othrys, not even during the latter's weekly Sunday dinners. While he claimed to be too busy, Kronos knew that the actual reason was Koios' secret fear of his brother's might and infamous temper.

Koios' daughter Asteria later married Perses (the Titan of Destruction), and gave birth to the goddess Hecate.

Zeus Rescues His Siblings

However, years later, after Kronos hired a young Titan by the name of Zeus (actually a god in disguise, Kronos' son in disguise), Koios was very entertained by the latter's excellent singing, dancing, and "Satyr jokes", and took to visiting Kronos on Mount Othrys much more often. Shortly thereafter, Zeus encouraged Koios to participate in the newly established Titanic drinking contests. As the Titan King of Mount Othrys, Kronos would always win, since he could not let his siblings or nephews overcome him in anything.

One evening, when Koios was dining with his brothers and nephews, Zeus prepared nectar mixed with sleeping potion for Koios, and a powerful emetic for Kronos. As before, Zeus entertained them all with his great singing, dancing, and jokes. Near the end of the Titanic banquet, Zeus encouraged all of the Titans to have yet another drinking contest, and handed out the prepared goblets. As before, Kronos won the contest, but the emetic caused him to disgorge all his swallowed children, from the last devoured to the first devoured (the boulder Rhea teplaced Zeus with as a desparate attempt to save him, Poseidon, Hades, Hera, Demeter and Hestia) while Koios was temporarily knocked out by the sleeping potion, and could not stop them from escaping.

First Titanomachy

Shortly thereafter, all six of Kronos' children quickly declared war against their father, as well as the other Titans, which resulted in the terrifying 11-year-long Titanomachy. Koios initially had the upper hand in his battles with the gods, since he was a very skilled and more experienced swordsman. However, the gods quickly became skilled warriors as well, and with the help of their new extremely powerful weapons (Zeus' Master Bolt, Poseidon's Trident, and Hades' Helm of Darkness), as well as the aid of the Elder Cyclopes and Hekatonkheires whom the gods freed from Tartarus once again after Kronos locked them up once more, the gods finally prevailed. During the final battle, Zeus used his Master Bolt to shear off the top of Mount Othrys, and hurl Kronos from his Black Throne, defeating the Titan King and cutting him up into a thousand pieces just with his scythe just as Kronos had done to his own father. Shortly thereafter, the gods invaded the ruins of Mount Othrys, and finally overwhelmed the remaining Titans (including Koios himself).

In the aftermath of the battle, Koios was chained up by the Elder Cyclopes, after which the Hekatonkheires forced him to kneel before Zeus, Poseidon, and Hades. Zeus proceeded to taunt his uncle Koios, prompting the latter to hang his head in shame. Zeus proceeded to hurl Koios into Tartarus, along with Hyperion, Iapetus, Krios, and Kronos' remains. The Titans would be imprisoned in the maximum-security zone of Tartarus, surrounded by huge bronze walls, and a lava moat, guarded by their Hekatonkheire brothers. Years later, Koios, briefly went crazy and tried to break out of Tartarus but was ultimately subdued by Cerberus.

Percy Jackson and the Olympians

The Last Olympian

After Kronos turned Luke Castellan against the Olympians, the Titans were slowly resurrected to take on the gods. Koios was one of the Titans who aided Kronos in the Second Titan War. Kronos and Hyperion led the Battle of Manhattan, while Oceanus (who was persuaded by Kronos to participate in the war this time) led the assault on Atlantis. Krios defended Mount Othrys. Iapetus attempted to overthrow Hades. It is unknown, however, what Koios' part in the war was if any. In Percy Jackson and the Olympians and The Heroes of Olympus there is never any mention of a fight with Koios. Iapetus lost his memory and never made it out, Hyperion was beaten by Percy, Hermes said "Krios fled" (when in fact he had been beaten by Jason), Oceanus went to the Ocean depths after Kronos was beaten and Promethius sent a list of reasons why he joined Kronos (proving he actually did go into hiding) but there is no mention of Koios being defeated by the Romans or Greeks. Theoretically, he might never have made it out of Tartarus.

The Heroes of Olympus

The House of Hades

After the Doors of Death were captured and opened by his mother Gaea, Koios was among the Titans and monsters who planned to return to the mortal world through the doors. Koios was reunited with his brother Iapetus, now known as Bob when he led Percy and Annabeth through Tartarus. During the Titan War, Iapetus's memory had been destroyed by Percy Jackson, when he tackled him into the River Lethe. In the Second Giant War, Iapetus defected to the side of the Olympians. Even as Tartarus healed his memory, Iapetus continued aiding Percy Jackson and his girlfriend Annabeth Chase, who had been thrown into Tartarus in a fight in Rome.

Hidden by the Death Mist, Percy and Annabeth were unseen by Koios mainly because of the death mist. The Titan assumed Iapetus's memory was returning and that he was returning to their side. Iapetus didn't counter him. Koios reminded Iapetus about their uprising against Ouranos, remembering how their father kicked Iapetus in the face. Koios planned to return in order to complete the Titans' takeover of Mount Olympus, believing that Gaea would eventually remember that the Titans were her eldest children and forget about the Gigantes. He also hoped to persuade his daughter Leto to join them in their conquest, believing that she will agree to side with the Titans, after the way Zeus treated her after the birth of Apollo and Artemis. Koios hurried off, assuring Iapetus that he would later meet up with their brothers Hyperion and Krios at the entrance to the Doors of Death.

Koios's plans were thwarted when Iapetus ultimately betrayed the Titans and aided Percy and Annabeth against the Titans, monsters, and the lord of the pit, Tartarus. With the help of the peaceful Gigante Damasen, Iapetus held the elevator's button, knowing that Percy and Annabeth were needed in the war against Gaea. Due to Iapetus's and Damasen's sacrifice, Percy and Annabeth returned from Tartarus and the Doors of Death were closed, imprisoning Koios inside Tartarus. It is unknown what happened to him after that.


Koios was roughly 10 feet tall, with elaborate black Stygian Iron armor and a single diamond blazing in the breastplate. His eyes were blue-white and as cold as a glacier. His hair and beard were blue-white, with his hair cut in military style. He wore a helmet shaped like a bear's head, and wielded a massive sword the size of a surfboard, which radiated "more cold than Hubbard Glacier". His face, though marked by a number of battle scars, is quite handsome, and according to Percy, Koios had the same cold eyes as Artemis, with the same bright smile as Apollo, as he is their grandfather.


In Percy Jackson's Greek Gods, Koios is revealed to be extremely intelligent, wise and capable of predicting the future. As a result, Koios was frequently approached by all of his siblings, asking him questions. Apparently, even Kronos held Koios in great esteem, and he didn't question Rhea's decision to give birth to Zeus on Crete when she claimed that the clairvoyant Koios advised her to. As seen in The House of Hades, Koios is also quite cruel and arrogant, like the rest of his Titan brethren, since he believed that his race, the Titans, were superior children of Gaea and more sophisticated than the Giants and the Olympians alike. However, Koios seems to be on good terms with his fellow Titan brothers, as he seems very upset about Kronos permanently losing his body, and greeted Iapetus enthusiastically, cheerfully recounted their conquest against their father, and vows revenge on Hades for enslaving him. He also seems to love his daughter Leto, lamenting that she would not join the Titans' cause, but has no such affection for his grandchildren Apollo and Artemis or his nephew Hades. He is also quite eloquent in his manner of speech, making it sound like he was "reciting Shakespeare" to Percy.


No abilities of Koios have been shown, but the following can be inferred:

  • Prowess in Battle: As an Elder Titan, Koios is very powerful, though not as much as his brothers Hyperion and Kronos and his nephew Atlas. He, apparently, actively participated in the second Titanomachy, though he was ultimately defeated. His weapon of choice implied that Koios was an excellent swordsman.
  • Keen Intellect: As the Titan of Intellect, Koios was extremely intelligent (and certainly the smartest one of his siblings), shown by his sophisticated and refined manner of speech. As seen in Percy Jackson's Greek Gods, Koios' wisdom and intelligence were held in great esteem by Kronos himself.
  • Prophecy: In Percy Jackson's Greek Gods, Koios is revealed to be the only Titan with the power of accurately predicting the future. He could ask the sky questions, while the answers would frequently be whispered back to him. As a result, all of Koios' siblings would frequently approach him with questions about the future. This is also the gift Apollo Inherited many, many years later.
  • Cryokinesis: As the Titan of the North, Koios has the ability to manipulate snow, ice and frost, as his sword radiated "more cold than Hubbard Glacier."
  • Omni-senses: As The Titan of Farsight he can potentially see everything.
  • Titanic Energy: Like all Titans, Koios has the ability to blast things hundreds of yards away from himself with a yell or a wave of the hand.
  • Titanic Divine Form: As Kronos's elder brother, it is possible that Koios also had the ability to incinerate any being less than a god/Titan only by being present.
  • Tongue of the Old Times fluency: According to Tyson in The Battle of the Labyrinth, this is the ancient language that Gaea spoke to the Titans, Elder Cyclops and Hekatonkheires before the birth of the Olympian gods. Hence, Koios understands and speaks it perfectly.


  • Koios was not well known in Greek mythology, and even less in Roman mythology, where he was known as Polus. He was mainly mentioned on a list of Titans. He's only considered prominent in the history of the Greco-Roman deities.
  • His Norse Female Counterpart is Frigg because she is the Norse Goddess of Foresight.
  • Koios is the only known Titan that never appeared and was never even mentioned in the first book series. Thus, it is unknown what Koios' role in the Second Titanomachy was.
    • Even though he was never mentioned or appeared in the first book series, his descendents are quite important to the series.
  • Koios is the only Titan with the gift of prophecy, and he is the grandfather of Apollo.
  • Apparently, even Kronos held Koios in great esteem, and he didn't question Rhea's decision to give birth to Zeus on Crete when she claimed that the clairvoyant Koios advised her to.
  • As revealed in Percy Jackson's Greek Gods, while waiting in ambush to attack their father with his brothers, Koios hid in a deep pit, which he covered with leaves and twigs.
The Heroes of Olympus
Core Series: The Lost Hero | The Son of Neptune | The Mark of Athena | The House of Hades | The Blood of Olympus
Main Characters: Jason Grace | Piper McLean | Leo Valdez | Percy Jackson | Frank Zhang | Hazel Levesque | Annabeth Chase | Reyna Ramírez-Arellano | Nico di Angelo | Gleeson Hedge
Secondary Characters: Hylla Ramírez-Arellano | Dakota | Tyson | Ella | Octavian | Halcyon Green | Dr. Howard Claymore | Alabaster C. Torrington | Lamia | Iapetus/Bob
Minor Characters: Rachel Elizabeth Dare | Grover Underwood | Thalia Grace | Fleecy | Mrs. O'Leary | Kinzie | Arion | Calypso | Lou Ellen Blackstone | Chiron | Will Solace | Tristan McLean | Don | Julia | Jacob | Michael Varus | Burly Black | Medea | Midas | Lityerses | Phineas | Otrera | Echo | Narcissus | Sciron | Pasiphaë
Olympian Gods: Zeus | Hera | Poseidon | Hades | Ares | Demeter | Athena | Apollo | Artemis | Hephaestus | Aphrodite | Hermes | Dionysus
Minor Gods: Achelous | Aeolus | Asclepius | Boreas | Eurus | Hecate | Iris | Hypnos | Keto | Khione | Kymopoleia | Mithras | Nemesis | Nike | Notus | Phorcys | Serapis | Thanatos | Triptolemus | Zephyros
Roman Gods: Jupiter | Juno | Neptune | Pluto | Mars | Minerva | Ceres | Lupa | Bellona | Fortuna | Janus | Terminus | Vulcan | Mercury | Apollo (Roman) | Diana | Venus | Bacchus | Pomona | Aquilon | Hercules | Cupid | Auster | Favonius | Letus | Victoria
Giants: Enceladus | Porphyrion | Alcyoneus | Polybotes | Ephialtes | Otis | Damasen | Clytius | Mimas | Orion | Hippolytos| Thoon | Periboia
Undead: Gray
Primordial Gods: Gaea | Tartarus | Ourae | Nyx | Chaos | Ouranos | Akhlys | Hemera | Elpis | Spes
Monsters and Magical Creatures: Cynocephali | Gorgon | Gryphon | Harpy | Basilisk | Lycanthrope | Gegeines | Cyclops | Katobleps | Unicorn | Giant Eagle | Ichthyocentaur | Satyr/Faun | Storm Spirit | Laistrygonian Giant | Lares
Related Content: Rick Riordan | Haley Riordan | Percy Jackson and the Olympians | Percy Jackson and the Olympians: The Ultimate Guide | The Demigod Files | The Demigod Diaries | The Son of Sobek | The Singer of Apollo | The Staff of Serapis | Percy Jackson's Greek Gods | Percy Jackson's Greek Heroes | The Crown of Ptolemy | Demigods & Magicians | Demigods of Olympus | Percy Jackson Demigod Collection