With the size as  a rhinoceros, the hippopotamus rivals rhinoceros as the second  biggest land animal. It may be surprising, but being a fat animal, the hippopotamus is a plant eater. Its ears, eyes, and nose are situated high up on the face allowing them to be totally submerge water, since they spend most of the day lying in the water. Hippopotamus  lives in a group and can live up 50 years.