In Ancient Greek k?t?s (, plural k?t?=k?tea, ?, ), Latinized as cetus (pl. ceti or cet? = cetea), is any huge sea creature or sea monster. According to the mythology, Perseus slew Cetus to save Andromeda from being sacrificed to it. In a different story, Heracles slew Cetus to save Hesione. The term cetacean (for whale) derives from cetus. In Greek art, ceti were depicted as serpentine fish. The name of the mythological figure Ceto is derived from k?tos. The name of the constellation Cetus also derives from this word.
Queen Cassiopeia boasted that she and her daughter Andromeda were more beautiful than the N?r?ides (in most later works called by the Roman form, the Nereids), which invoked the wrath of Poseidon who sent the sea monster k?t?s (in a far greater number of European works renamed as the Latinised Cetus) to attack Æthiopia. Upon consulting a wise oracle, King Cepheus and Queen Cassiopeia were told to sacrifice Andromeda to Cetus. They had Andromeda chained to a rock near the ocean so that Cetus could devour her. After finding Andromeda chained to the rock and learning of her plight, Perseus managed to slay Cetus when the creature emerged from the ocean to devour her. According to one version, Perseus drove his sword into Cetus's back, while according to another version, he used Medusa's head to turn the monster into stone.
The Cetus was variously described as a sea monster or sea serpent. Other versions describe Cetus as a monster with the head of a boar or a greyhound and the body of a whale or dolphin, and a divided, fan-like tail. It is often depicted fighting Perseus or as the mount (animal being ridden) of a Nereid.
Tanninim () (-im denotes Hebraic plural) appear in the Hebrew Book of Genesis, Exodus, Deuteronomy, Psalms, Job, Ezekiel, Isaiah, and Jeremiah. They are explicitly listed among the creatures created by God on the fifth day of the Genesis creation narrative, translated in the King James Version as "great whales". The Septuagint renders the original Hebrew of Genesis 1:21 (hattanninim haggedolim) as ? (k?t? ta megala) in Greek, and this was in turn translated as cete grandia in the Vulgate. The tannin is listed in the apocalypse of Isaiah as among the sea beasts to be slain by Yahweh "on that day", translated in the King James Version as "the dragon".[n 1]
In Jewish mythology, Tannin is sometimes conflated with the related sea monsters Leviathan and Rahab. Along with Rahab, "Tannin" was a name applied to ancient Egypt after the Exodus to Canaan.
In Jonah 2:1 (1:17 in English translation), the Hebrew text reads dag gadol ( ?), which literally means "great fish". The Septuagint translates this phrase into Greek as mega k?tos (? ). This was at the start of more widespread depiction of real whales in Greece and k?tos would cover proven whales, sharks and the old meaning of curious sea monsters. Jerome later translated this phrase as piscis grandis in his Latin Vulgate. However, he translated the Greek word k?tos as cetus in Gospel of Matthew 12:40. The English opts for the former: "For as Jonah was three days and three nights in the belly of a huge fish, so the Son of Man will be three days and three nights in the heart of the earth."
Cetus is commonly used as a ship's name or figurehead denoting a ship unafraid of the sea or a ruthless pirate ship to be feared. Ceti were widely viewed as misfortune or bad omen by sailors widely influenced by the Mediterranean traditions such as the bringer of a great storm or general harbinger. Lore and tales associated it with lost cargo and being swept off course, even pirates being allied with such creatures so as to become taboo aboard vessels.
Art historian John Boardman conjectured that images of the k?tos in Central Asia influenced depictions of the Chinese Dragon and Indian makara. They suggest that after contact with silk-road images of the k?tos, the Chinese dragon appeared more reptilian and shifted head-shape.