The most dangerous wild animal in Africa is surprisingly the mostly herbivorous hippopotamus.
The hippopotamus is a large semi-aquatic mammal, its name (ἱπποπόταμος) literally means the horse of the river. In English a hippopotamus is usually just called a hippo as we tend to shorten all sorts of words — which sounds somewhat funny since ἵππος (hippos) means horse in old Greek).
The hippopotamus is semi-aquatic and prefers to be in the water on a hut summer day.
An adult hippopotamus can weigh about one and a half metric tonnes and it is considered to be the largest land mammal after the elephants and rhinoceroses. This is also funny a bit as hippopotamuses are not really land mammals entirely and they are somewhat the small ones among their relatives who are surprisingly the cetaceans such as whales and dolphins.
Hippopotamus (Hippopotamus amphibius) having a nap on the sun in the Toronto Zoo.
Hippopotamuses kill more humans in Africa each year than any other animal, including predators such as lions and crocodiles. Even though they look like peaceful and lazy, looks can be deceiving. Hippopotamuses are incredibly aggressive, can be quite fast (easily outrun a human) and usually will try to kill you if you bother them. As someone has pointed out to me while other animals will just try to chase you away, a hippopotamus will actually chase after you and kill you. If you hope to live to a ripe old age try avoid harassing hippopotamuses when you are in Africa.
Hippopotamus emerging from the water showing its teeth.
Make no mistake, those are deadly weapons.
This murderous rage is not limited to humans, hippopotamuses kill crocodiles and other animals that show up in their territory. They are aggressive even towards their own species and males will fight with each other in order to decide who gets to rule a territory. Apparently it is customary for the winner to at least maim the looser by biting off its tail.
A cast of a hippopotamus skull exhibited in the Toronto Zoo.
Those teeth are exactly as dangerous as they look.
Hippopotamus meat is edible and people in Africa sometimes do eat it even though it is said to be incredibly tough. In most developed countries it is actually illegal to sell hippopotamus meat.
Hippopotamuses have very tough skin that can even stop a small bullet — your gun better be loaded for elephant if you go hippopotamus hunting because it probably will find being shot at a good reason why it needs to chase you and kill you which in this case it would be justifiable self defense.
Further Readings:
Hippo on out to Africa.
Video: World’s Deadliest: Hippo vs. Hippo on National Geographic.
Secretion protects skin: Hippopotamus on asknature.org.
Hippopotamus on Wikipedia.