As with many constellations, there is no one specific creature represented by CETUS.
To the ancient Babylonians it was the great sea monster Tiamat, symbolising Chaos.
It has been depicted by some as a sea-serpent or dragon fish, whilst others saw
it as a great whale. But it is probably best known as the sea monster sent by
Poseidon to devour Andromeda. Fortunately for her,
Perseus arrived on the scene
just in time to slay the dreaded monster and claim Andromeda as his bride.