seems statistics support either hippo or crocodile, but crocodiles not limited to africa

likely vast majority of victims of hippos (and others) are locals rather than tourists
tourists etc may ignore hippos while being more cautious regarding crocodiles

straightdope.com/columns/read/1862/are-hippos-the-most-dangerous-animal

interestingly, (deadliest) snake/spider venom is not fatal for average adults
although that may sometimes be based on treatment, not always available
perhaps similar to ebola not being fatal with sophisticated treatment