This is the article on the family Hippopotamidae; for the main article on hippos, see Hippopotamus

Hippopotamuses are stout, naked-skinned, and amphibious artiodactyl members (and the only living members) of the family Hippopotamidae possessing three-chambered stomachs and walking on four toes on each foot. While they resemble pigs physiologically and are pseudoruminants like camels, their closest living relatives are actually the cetaceans (whales and dolphins).