Blue Whale
Balaenoptera musculus
Status: Endangered. Commercial whaling in earlier centuries greatly reduced their global numbers, and current primary threats are environmental changes, vessel strikes, and ocean noise. Because whales are so enormous and long-lived, they accumulate a significant amount of carbon in their bodies during their lifetime. Blue whales help to regulate krill populations, which are tied to the populations of phytoplankton and algae on which they feed.
In Ancient Greek myths, cetea were leviathan sea creatures. The Ancient Greeks imagined them as sea monsters, but they were most likely inspired by sights of enormous whales.
Queen Cassiopeia of Aethiopia was a vain woman, not only of herself, but she was also overly proud of her daughter Andromeda's beauty. She boasted that Andromeda was more lovely than the Nereids (sea nymphs). This angered Poseidon, god of the sea, who sent a sea monster Cetus to attack the city of the boastful queen.
The king and queen belatedly became fearful. They consulted an oracle, who told them they must sacrifice their daughter Andromeda to appease Poseidon. In great distress, but with no other alternative for salvation, they set about to do so, but the hero Perseus swooped in and managed to save the day by defeating the sea creature and rescuing Andromeda from her dire fate.
References:
Papadopoulos, J. K., & Ruscillo, D. (2002). A Ketos in Early Athens: An Archaeology of Whales and Sea Monsters in the Greek World. American Journal of Archaeology, 106(2), 187-227. https://doi.org/10.2307/4126243
Thomas Bulfinch (1855). Age of Fable: Beauties of Mythology. S.W. Tilton & Co, Boston pp 163-167. http://www.online-literature.com/bulfinch/mythology_fable/9/ https://www.google.com/books/edition/The_Age_of_Fable/Y5cZAAAAYAAJ?hl=en&gbpv=1&bsq=perseus