Ceto
Κητώ
Mother of the Gorgon sisters. Her name is literally the Greek word for "sea monster."
Daughter of Pontus and Gaia, she bore the Graeae and the Gorgon sisters to her brother Phorcys.
Ketos was an ordinary noun for any huge, unidentifiable sea beast — whale or shark or otherwise. This goddess wears that word as her name.
The constellation Cetus and the word cetacean come from the same root — and the sea monster that came to devour Andromeda was also called a ketos.
SourcesHesiod, Theogony