The hippopotamuses are most dangerous for humans. Unfortunately hippos like to hang out near slow-moving fresh water. Most accidents occur because people are out walking at night, just the time when hippos leave the water to graze. Being trampled by a startled hippo is not a dignified way to die. Hippopotamuses, once believed to be members of the pig family but now shown to be most closely related to whales, are divided into two species. The common hippo is the third largest land mammal after the African and Asian elephants.

They are very irritable beasts, especially when they have young. They dispose of lions by plunging them into deep water and drowning them, crocodiles by biting them in half, and sharks by dragging them out of the water and trampling them to death. However, they are strict vegetarians, so their aggression is mostly to do with self-defence. Hippos mainly eat grass.