Mike Tyson's face tattoo.
2
I'm going to go against the grain here. Iron Mike has made a career of being scarier, crazier, and more intimidating than anybody else. When his actual boxing skills deserted him (which was a long, long time ago), all he had left was this frightening mystique. What better way to play to his last remaining strength than getting a tattoo on his face, making him look even scarier and crazier than he did before? A face tattoo was probably one of the more prudent career moves ever made by Mike Tyson.