Squids are marine cephalopods, a class that includes octopus and cuttlefish among others.
Squids have eight arms and two tentacles, a mantle which is the main body mass and a distinctive head.
Squids have a skin covered of chromatophores, special cells which enable squids to change colors to camouflage.
Although most squid are no longer than 60 cm, the Giant Squid can reach up to 13 meters or 43 feet in length. However, it is not the largest squid; recently the Colossal Squid was discovered. This species reach up to 14 meters of 46 feet in length, making it the largest invertebrate.