Hugo is a young male Hippopotamus living in Zambia's Luangwa River. He lives with his mother in a stretch of river ruled by his Dad, 'the King of the River' -- the biggest, loudest, grumpiest Hippo on the river. They share this territory with many other mothers and babies, but males are only tolerated if they submit to 'the King'. If not, they will have to fight, Hippos may look clumsy on land, but in reality they can run at over 40 kmph -- that's faster than an Olympic sprinter. Hugo is learning who his friends are: the Oxpeckers that keep a hippo clean and parasite-free above water, and the fish that clean his skin and teeth below water. Hippos have enemies too. But the greatest enemy of all is Zambia's changeable weather.