Any of you old timers remember "Classy" Freddie Blassie? I read his autobiography a few years ago. He's remember mostly now for his years as THE PREMIER heel manager, but he was quite the wrestler, in his own right. He was legitimately insane!
During Blassie's career, he'd been stabbed, had acid thrown on his back. At one point, he filed his teeth into points. He was so feared in Japan, it has been reported that he gave many viewers heart attacks, and some even died!
Probably the greatest heel in wrestling history, and certainly one of the most respected pros ever in the business. Certainly a HUGE influence on every heel character that has laced up a pair of boots.