The giant squid is a bus-length deep-sea animal with eyes as big as footballs, and one of the least-seen creatures on Earth.
A giant squid can be as long as a bus, with eight arms and two extra-long tentacles.
Females reach about 12–13 metres. It lives 300–1,000 metres down where the sea is dark, cold and crushing, and it uses its two long tentacles to grab food from far away.
A giant squid has blue blood and skin that can change colour in a flash.
Its blood carries copper instead of iron, which works well in cold deep water. Thousands of tiny colour cells in its skin let it turn dark or light very quickly.
A giant squid has eyes about as big as a football, and a beak strong enough to crack a crab.
Its eyes are around 25–27 cm across, which helps it catch the faintest light in the deep sea. In the middle of its arms is a hard beak like a parrot's, strong enough to break up fish and crabs.
A giant squid's biggest enemy is the sperm whale.
Sperm whales dive deep to hunt them, and many carry round scars on their heads left by the squid's suckers.
A giant squid eats fish, shrimp and crab — and was not photographed alive until 2004.
It also eats smaller squid and other deep-sea creatures. Japanese scientists took the first photo of a living giant squid in 2004, and the first video came only in 2012.
A giant squid lives only three to five years, and is shy rather than a monster.
It grows from a tiny baby to tens of metres in just a few years — one of the fastest growth rates of any animal. Old stories call it a sea monster, but it avoids people and there is no reliable record of one attacking anybody.
A giant squid keeps most of its life a secret from scientists.
Nobody knows for sure how they breed, where most of them live, how far they travel each day, or how many there are in the world.
A giant squid lives where sunlight never reaches.
Its eye is as big as a football, sperm whales dive more than 2 km down to hunt it, and its home is so dark and hard to reach that much about it is still a mystery.
Quiz time: what do you know about the giant squid?
Seven questions to try: how many arms and tentacles does it have? How big are its eyes? What hunts it? Does it live in shallow water or the deep sea? Why is its blood blue? How does it move? When was it first photographed in the wild?
