Hippopotami are giant creatures. They may seem docile, but when their territory is threatened they can be vicious. Some authorities list the hippopotamus, the world's third largest land animal, as one of the most deadly. They often will attack without apparent provocation, and at 1.5 to 3 tons, their attacks are swift and savage.
Hear the description of a hippo attack from these South Africans and see the injuries. via Animal Planet
