The last thing you want to do while diving in a river is to run face first into a hippo.
“Although hippos may look cute and friendly, they are definitely one animal you do not want to cross. Easily frightened and extremely aggressive, hippos will not hesitate to attack a human, especially if one of its young babies are near. Hippos pose the biggest threat to those living in the continent of Africa.”
With a yearly human death toll of over 300, these are creatures you want to stay away from.