Squid are a group of large cephalopod animals or types of mollusks that live in the sea. The name ‘’Cephalopoda’’ in Greek means “head of the head”, this is because the legs are separated into a number of arms wrapped around the head. Like all cephalopods, squid are separated by having a distinct head. The large axon of this squid has a diameter of 1 mm. Squid are widely used as food.