Hippopotamidae

Hippopotamidae is a small family of large, semi-aquatic mammals that includes the common hippopotamus and the pygmy hippopotamus. Members of this family have massive, barrel-shaped bodies, thick hairless skin, and large tusk-like incisors and canines. Native to sub-Saharan Africa, they spend much of their time in rivers and lakes to regulate body temperature, emerging at night to graze on grasses.