A hippopotamus stepped on the heels of the rhinoceros and attempted to sniff or lick the curious fellow creature. The understandably irate rhino turned around, opened his mouth and refused to leave. After a few minutes, the rhinoceros got tired of the "attention" and pricked the hippo with its horn. After that, the animal ran away for a while, but soon returned. Hippos are responsible for more human fatalities each year in Africa than any other large animal.