The Giant squid is the second largest mollusc and invertebrate. There are as many as eight different species of Giant squid and they have been found worldwide. The only squid larger than the Giant squid, is the Colossal squid.

The Giant squid has reverse sexual dimorphism, which means that females are larger and heavier than males. Females can grow to the size of 43 feet long and weigh up to 610 pounds. The males only grow up to 33 feet long and weigh 310 pounds. There have been reports of Giant squid up to 66 feet long, but no squids of that size have ever been scientifically documented. The Colossal squid and several prehistoric squids were slightly larger than the Giant squid. They live around 300 to 1000 meters below the ocean surface.

Very little is known about the reproductive cycle of this animal. However, many scientists believe the squid reaches sexual maturity around 3 years old. There is also much debate on how the male impregnates the female. In recent years, post-larval juveniles have been found of the coasts of New Zealand, and there are plans to capture more and maintain them in an aquarium.

Giant squids usually feed on deep-sea fish, other squid species and at times small whales. They catch prey with their tentacles, gripping it with the serrated sucker rings, which cover the underside of their appendage. The squid then brings the prey, usually still alive, up to its powerful beak, where its razor sharp tongue shreds the flesh off it as they devour it. The beak of a giant squid is so strong it is thought to be able to bite right through steel cable. Giant squids have also preyed upon humans. In the 1930s, Giant squids attacked three different ships. Fortunately for the occupants of the ships, all survived. The ships were simply too big and tough as they were made of steel for the squid to sink. The Giant squid retreated to the deeps when it was badly injured on the ships propellers. During World War 2, a group of sailors were attacked when their ship sunk in the Atlantic Ocean, almost all the crew survived except one very unlucky individual who was devoured.

The Giant Squid has very few predators. Sperm Whales will occasionally attack adult squids, yet often the squid fights back and the whale is badly hurt or even killed. Deep-sea sharks will dine on juvenile giant squids, yet once they reach full maturity, they are far too big and aggressive for sharks to prey on.

Many aquatic monsters of myth and legend have been based on the Giant squid. The Kraken is a perfect example of this. In ancient times, it attacked small wooden boats, destroying them and eating the crew. Today, we know much more about this fearsome giant of the deeps but yet still not near enough. They are elusive to us and it was not until recent years that we even got video footage of one. We are yet to learn about all that live in the deepest darkest parts of our oceans and the Giant squid, may simply be a miniature of something far larger and scarier we are yet to see.