Dr. Joy Reidenberg talks about one of the most elusive and mysterious creatures on earth, the giant squid. The documentary “Inside Nature’s Giants: Giant Squid” follows Dr. Reidenberg and a team of scientists as they investigate the sea creature, which has a razor sharp beak, teeth on its tentacles and tongue, a throat that dives through the middle of its brain and three hearts that power blue blood through a muscle filled jet-propulsion cloak. “Inside Nature’s Giants: Giant Squid” airs on WNET June 23.