Despite its docile appearance, it's best not to annoy a hippo. Even crocodiles are wary of this 3-tonne colossus with impressive teeth. This semi-aquatic animal lives along Africa's rivers and spends its days submerged in the water to keep cool. It is only at nightfall that it comes out onto dry land to feed on fresh grass (up to 40 kg per day). The hippopotamus is easily recognisable! It has a bulky frame, small ears, short legs and an enormous snout with impressive teeth. The hippos live in groups of around 15 members and observe a strict hierarchy.