Answer: Hippopotamuses

Hippopotamuses are a curious creature to behold even in the present day, let alone upon encountering them for the first time in the ancient world. To that end, when the Ancient Greeks encountered the enormous and broad-chested hippopotamuses in Africa, they named them within the context of what they understood, by relating them to horses.

The word we use to describe the creature today, hippopotamus, is a nod to the name the Greeks gave to them millennia ago that means “river horse”, a combination of hippos (horse) and potamos (river). If you’re curious if any other creatures got a similar treatment, the sea horse was originally known as the “hippocampus” or “horse sea monster” (hippos and kampos) and that designation lives on in the scientific classification of the tiny sea creatures.