Watch as this hippo chases off a group of lions from the river. The hippopotamus is extremely territorial and will defend their territory from most animals, including lions and crocodiles. A hippo ran run on land at up to 50 km/h. Underwater, they can run across the riverbed at 8 km/h, which is much faster than a lion can swim. Watch Killer Safari on Fridays at 8pm on National Geographic WILD UK. | National Geographic UK