Ключевые слова: africa, african, aggressive, animal, animalia, big, biology, breeding, captivity, chordata, closeup, danger, dangerous, diagonally, ears, eye, fat, head, hiding, hippo, hippopotamus, hippopotamus amphibius, huge, large, mammal, natural, nature, nose, portrait, river, river horse, submerged, swimming, water, wild, wildlife, zoo, zoological,