Legends of monster squids or kraken are probably based on sightings of the giant squid, a deep-sea animal known to live in the waters off Norway and Greenland where the kraken legend arose. Giant squids can reach up to 50 feet in length if their tentacles are included.
Giant squids are difficult to observe, as they live deep underwater. Most of what scientists know about these animals came from examination of stranded specimens. The Japanese research team of Tsunemi Kubodera and Kyoichi Mori obtained the first photographic images of a giant squid in its natural habitat in 2004. Eight years later, researchers from Japan's National Science Museum collaborated with Japanese public broadcaster NHK and the Discovery Channel to capture the first video footage of a giant squid in its natural habitat.