Fate/Grand Order's depiction of the sea monster from Greek mythology. Andromeda was chained to a rock to be sacrificed to it by her father, only to be rescued by Perseus using Medusa's head to turn the monster to stone.
As a servant, Andromeda utilizes the fact that she was chained to a rock along with Cetus' being turned to stone in order to summon it as her Noble Phantasm, Aethiopia Cetus.
