This people in the left picture is not a body modifications fans who modify his head into a horn like head. but unfortunately this man has that horn because of a tumor.
In Wuzhen from Xingyang county, Zhang Yuncai, 88 accidentally found a small pimple on his head when he had washed himself in May, 2006. From then on, the pimple grew bigger gradually and turned into a horn-shaped tumor protruding from his head. Now the horn-shaped bump is 5 centimeters long. Fortunately few heard about that news, and decided to operate him free of charge.
Here is the complete picture of Man with horn caused by tumor