After spending centuries obscured in myth, the real giant squid is finally becoming known to humans through photos and film taken by dedicated scientists and amateurs around the world.

When a 20-foot (6-meter) predator catches you off guard, will you know how to defend yourself? Learn why sharks attack and what you can do to keep your next encounter from being your last.

Gaze into the face of the frilled shark, a creature little-changed over millions of years and usually hidden in the ocean depths, thousands of feet below the surface.