![Pod of hippos in Luangwa Valley, Zambia](http://upload.wikimedia.org/wikipedia/commons/thumb/a/a3/Hippo_pod_edit.jpg/350px-Hippo_pod_edit.jpg)
Photo credit: Paul Maritz
The hippopotamus (Hippopotamus amphibius), from the Greek ‘ιπποπόταμος (hippopotamos, hippos meaning "horse" and potamos meaning "river"), is a large, mostly plant-eating African mammal, one of only two extant and three or four extinct species in the family Hippopotamidae.