The octopus is a mollusk. It lives in oceans around the world, from shallow reefs to the deep sea. This place is deep and salty.
The octopus eats crabs, shrimp and clams. It squeezes its soft, boneless body through tiny cracks to hide.
The octopus has eight arms covered in suckers. These grip rocks and pry open shells. It is about from a few centimeters to several meters across, depending on the kind.
Baby octopus are called hatchlings. A mother octopus guards her eggs for weeks and does not leave them, even to eat.