Represented as a whale, chief monster of the deep, the largest of the aquatic race. It is fittingly a large constellation.
Most writers consider this the famous sea monster who was sent by Neptune to gobble Andromeda up after her mother, Cassiopeia, bragged about how beautiful she was. You will recall how this monster got his come-uppance from Perseus. At any rate, its origin is buried somewhere in the mists of dark antiquity.
“The winged hero now descends, now soars,
And at his pleasure the vast monster gores.
Deep in his back, swift stooping from above.
His crooked sabre to the hilt he drove.”
It’s been established that this constellation had a place in the heavens long before Perseus. When the equinoctial sun in Aries (right over the head of Cetus) opened the year, it was nicknamed the “Preserver” or “Deliverer” by the idolaters of the East. According to Pausanias, this is why the sun was worshipped at Eleusis under the name of the “Preserver” or “Saviour”.