The constellation whose name is Latin for “whale” or “sea monster” is Cetus.
Cetus comes from the Latinized Greek word kētos, a broad term for a huge sea creature. Depending on context, it could mean a whale, sea monster, or similar ocean beast rather than one precisely defined animal. That explains why Cetus is translated in different references as either “the Whale” or “the Sea Monster.”
In Greek mythology, Cetus is the monster sent to threaten Andromeda; Perseus killed it while rescuing her. The constellation lies in a region sometimes called the celestial sea, near Pisces, Aquarius, Eridanus, and other water-associated figures. It was already among the constellations listed by the ancient astronomer Ptolemy.
Cetus is not a zoological portrait of a modern whale. Older sky maps show it in varied forms, including dragon-like or fish-like creatures. The constellation is also home to Mira, a famous long-period variable star, and Tau Ceti, a nearby Sun-like star often discussed in astronomy and exoplanet research.