The hippopotamus, whose hide alone can weigh half a ton, is the third-largest living land mammal, after elephants and white rhinos. The name hippopotamus comes from the Greek "hippos," meaning horse. These animals were once called "river horses“
Given the right conditions, a hippo can live up to 40 years.
When hippos bask in the sun, they secrete a red, oily substance. This has given rise to the myth that they ‘sweat blood’. The liquid is a natural sunblock and moisturizer.
Although it seems that hippos can submerge for inordinately long periods of time, they need to surface every 3-5 minutes to breathe. This is a natural reflex and can be done even when the animal is sleeping.
Despite their bulk, hippos can attain speeds of up to 30 km per hour over short distances.

They spend most of their time in the water although they leave the water in the cooler parts of the day and night in order to forage for vegetation. They have been known to walk up to 10km in order to find food. Considering their bulk, the fact that they can consume up to 68kg in a night is a relatively small amount.
Hippo’s are not only territorial in water, but it is also when they are out of the water that hippo can be extremely aggressive towards humans. They have been called the most dangerous animal in Africa as they have been known to cause many a death, especially in communities that are near or are surrounded by water.
Both reproduction and birth take place in water, and it is here that the huge bulls become fiercely territorial. Adult males have been known to injure or kill both females and youngsters when competing for space.
Hippos can neither swim nor float! They give that impression while they are in the water, when in fact they are walking along the bottom surface.
Often seen rearing up out of the water, mouth agape, this is not a yawn but a sign of aggression. Accompanied by a loud series of grunts and honks, it is a warning not to be taken lightly.