Its a large fat animal with a small brain (now if you are comparing to someone known its not my fault :P ) which feeds largely on leaves (its a vege I guess). Unfortunately traditional asian medicine's misconception that its horn is a "life saver", has led to poaching and smuggling. Unfortunately this foolish belief had led to a situation where the species is under the threat of extinction. I met a conservationist in Africa and he half jokingly told me "You Asian's are largely responsible for them to be endangered". This actually reminded me the amount of myths we Asians live with, starting from cat to crow we had made all of them mythical figures. In some cases it has helped the species existence and in other cases made them extinct.
Another misconception that people have about Rhinos are that since there are two species of Rhino's named as white rhino and the black rhino, hence they expect them to be differentiated on color. Unfortunately someone probably had made a mistake when naming them, both are similar in color but the difference is in their lips. So next time you go to a game park stop looking for a white color rhinos, since both species are actually gray :D