In Greek mythology, a Cetus (Ancient Greek Κῆτος, romanized Kêtos) is a large sea monster. The most famous was sent by Poseidon to ravage Aethiopia, where Andromeda was chained to a rock as a sacrifice; Perseus slew the creature to save her. In a separate tale, before the Trojan War, Heracles also killed a cetus to rescue Hesione. The word survives in modern terms such as "cetacean," and in Greek art ceti were depicted as colossal, serpentine sea-beasts.
Adapted from Wikipedia, "Cetus (mythology)" · CC BY-SA 4.0
I.Depictions
A cetus was described as a sea monster or sea serpent. Some versions depicted it with the head of a wild boar or greyhound and the body of a whale or a dolphin with divided, fan-like tails.
Ceti were imagined as colossal beasts the size of a ship: their skulls alone measuring some 40 feet (12 metres) in length, their spines a cubit in thickness, and their skeletons standing taller at the shoulder than any elephant. In Greek art they were rendered as serpentine fish.
II.Greek mythology
Queen Cassiopeia boasted that she and her daughter Andromeda were more beautiful than the Nereids, angering Poseidon, who sent a cetus to attack Aethiopia. An oracle instructed King Cepheus and Queen Cassiopeia to sacrifice Andromeda, and they chained her to a rock by the ocean.
When Perseus discovered her predicament, he managed to slay the cetus as the creature emerged from the sea to devour her. According to one account, Perseus used the harpe given by Hermes; another version holds that he employed Medusa's head to turn the monster to stone. He then freed Andromeda and won her as his bride.
In a separate tale, set before the Trojan War, Heracles slew a cetus to rescue Hesione.
III.Etruscan mythology
In Etruscan mythology, the cetea were regarded as psychopomps, appearing frequently on sarcophagi and funerary urns alongside dolphins and hippocamps. The Etruscan sea deity Nethuns is sometimes depicted wearing a headdress in the form of a cetus.
IV.Bible and Jewish mythology
The monster tannin in the Hebrew Bible was translated as Greek kētos in the Septuagint and cetus in the Latin Vulgate. Tanninim appear throughout multiple biblical books and are explicitly listed among the creatures created by God on the fifth day in Genesis, rendered in the King James Version as 'great whales.'
In Jewish mythology, Tannin is sometimes conflated with the related sea monsters Leviathan and Rahab. Along with Rahab, the name 'Tannin' was applied to ancient Egypt after the Exodus to Canaan.
In the Book of Jonah, the Hebrew text reads dag gadol ('great fish'). The Septuagint translates this as mega kētos. Jerome later rendered it as piscis grandis in the Vulgate, though he translated kētos as cetus in Matthew 12:40.
V.In other cultures
Art historian John Boardman conjectured that kētos imagery in Central Asia influenced depictions of the Chinese dragon and the Indian makara. Boardman suggested that, following Silk Road contact with kētos imagery, the Chinese dragon came to appear more reptilian and shifted in head-shape, in contrast to the earlier pig dragon with its boar-like head.
VI.Ships and sailing
Cetus, or megakētēs, was commonly used as a ship's name or figurehead, denoting a ship unafraid of the sea or a ruthless pirate ship to be feared. At the same time, ceti were widely viewed by sailors as a sign of misfortune or bad omen, associated with storms, lost cargo, and being swept off course.