Warning: Graphic Imagery
When a shark bites this man's arm, he returns the favor by squeezeing the shark's gills hard with his knees. Though he survives the attack when the shark releases him, the arm cannot be saved. In retribution for his lost limb, the man goes on a killing rampage, vowing to "kill every shark he sees."
Eventually he hooks a hammerhead shark that fights for over an hour. He prevails, but marvels at this creature who fought so hard for its life and makes a change. via Discovery