The creature known for having eight tentacles is the octopus. Octopuses belong to the class Cephalopoda and are highly intelligent marine animals. They are characterized by their soft-bodied nature, a bulbous head, and those eight flexible arms lined with suckers. Octopuses are adept at camouflage, able to change their color and texture to blend in with their surroundings. They also have remarkable problem-solving skills and can escape enclosures, showcasing their dexterity and intellect. Their unique physiology includes a central brain and a decentralized nervous system with a significant number of neurons in their arms.