Cephalopod attack
Cephalapod attacks on humans have been reported since ancient times. A significant portion of these attacks are questionable or unverifiable tabloid stories. Cephalopods are members of the class Cephalopoda, which includes all squid, octopuses, cuttlefish, and nautiluses. Some members of the group are capable of causing injury or death to humans. Defenses. Tentacles. Tentacles are the major limbs used by squid for defense and hunting. They are often confused with arms—octopuses have eight arms, while squid and cuttlefish have eight arms and two tentacles. These tentacles are generally longer than arms and typically have suckers only on  their ends instead of along the entire length. The giant squid and colossal squid have some of the largest tentacles in the world, with suckers capable of producing suction forces of more than ) and with pointed teeth at the tips. Beak. The cephalopod beak resembles that of a parrot. It is a tough structure made of chitin and marks the beginning of the cephalopod's digestive system. Colossal squid use their beaks for shearing and slicing their prey's flesh to allow the pieces to travel the narrow esophagus. One of the largest beaks ever recorded was on a colossal  squid. The beak had a lower rostral length of . Many beaks have also been discovered in the stomachs of sperm whales, as the stomach juices dissolve the soft flesh of the squid, leaving the hard beaks behind. The largest beak ever discovered in this way had a lower rostral length of , indicating that the original squid was . Venom. All octopuses have venom, but few are fatally dangerous. The greater blue-ringed octopus, however, is considered to be one of the most venomous animals known; the venom of one is enough to kill ten adult humans. It uses the neurotoxin tetrodotoxin , which quickly causes respiratory arrest. Estimates of the number of recorded fatalities caused by blue-ringed octopuses vary, ranging from seven to sixteen deaths; most scholars agree that there are at least eleven. Attacks on humans. Common octopus. While octopuses generally avoid humans, attacks have occasionally been verified. For example, a Pacific octopus, said to be nearly perfectly camouflaged, approached a diver and attempted to wrap itself around the diver and his camera. Another diver recorded the encounter on video. The divers speculated that the octopus may have thought its reflection in the camera lens was a smaller octopus, which  may have motivated it to attack. The supposed attack on a Staten Island ferry in New York, leading to the loss of the ferry and commemorated by a bronze sculpture (installed in 2016), never actually occurred, nor was there any such ferry disaster. The artist responsible admitted it was "a multimedia art project and social experience – not maliciously – about how gullible people are". In the 1960s, divers would willingly grapple octopuses in octopus wrestling, a then-popular sport in coastal United States.