Key Points

- Massive sea serpents

- Perseus famously defeated a Cetus to save Andromeda

Brief Bio

A cetus was variously described as a sea monster or sea serpent. Other versions describe a cetus as a sea monster 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 said to be colossal beasts the size of a ship, their skulls alone measuring 40 feet (12 meters) in length, their spines being a cubit in thickness, and their skeletons taller at the shoulder than any elephant.

There are notable physical and mythological similarities between a cetus and a drakōn (the dragons in Greek mythology), and, to a lesser extent, other monsters of Greek myth, such as Scylla, Charybdis, and Medusa and her Gorgon sisters.

Cetus are often depicted fighting Perseus or as the mount of a Nereid.

Queen Cassiopeia boasted that she and her daughter Andromeda were more beautiful than the Nereids, which invoked the wrath of Poseidon who sent the sea monster Cetus to attack Æthiopia. Upon consulting a wise oracle, King Cepheus and Queen Cassiopeia were told to sacrifice Andromeda to the Cetus. They had Andromeda chained to a rock near the ocean so that the cetus could devour her. After finding Andromeda chained to the rock and learning of her plight, Perseus managed to slay the Cetus when the creature emerged from the ocean to devour her. According to one version, Perseus slew Cetus with the harpe lent to him by Hermes. According to another version, he used Medusa's head to turn the sea monster to stone.

In a different story, Heracles slew a Cetus to save Hesione.

A Cetus had also been portrayed to support Ino and Melicertes when they threw themselves into the sea instead of a dolphin to carry Palaemon.