The Hippopotamus is in the family Hippopotamidae.
They are huge animals, weighing between 3,300 and 4,000 lbs (1500–1800 kg) and reaching lengths of 13 feet (4 meters) and heights of five feet (1.5 meters). Hippos live 40 to 50 years long.
Rivers and swamps in sub-Saharan Africa. The pygmy hippo weigh about an eighth as much and lives in the forest of West Africa.
Humans, crocodiles and lions
Although they spend most of their time in rivers and lakes, hippopotamuses leave the water at dusk to feed on grass. They can eat 100 pounds of food a night! While in the water, they typically sink to the bottom of lakes and rivers and walk or bound along the bottom. When underwater they close their nostrils. Hippos are very aggressive. They are territorial about a stretch of water, with one dominant male being in charge of several females and their offspring. Males fight by ramming each other with their mouths open. Hippos are faster than humans! They can run 18 mph (29 km/hr) for a short time.