Some of the most beloved players in NFL history are also the most fearsome. Dynasties were built on defenses with names like the "Steel Curtain" and the "Purple People Eaters"; squads defined by vicious hitters like Jack Lambert and Carl Eller.
Players like these had the kind of reputations, and film, that intimidated opponents and transformed the NFL into the most popular sport in America.
As the NFL takes steps to protect players from head injuries, the biggest hitters of the new era are trying to follow rules without compromising their nature.
These are the guys you can expect to be the hardest hitmen of the 2012 NFL season.