Cephalopods are a class of mollusks that include creatures like octopuses, squids, and cuttlefish. They are known for their soft bodies, which are often highly flexible, and their ability to change color and texture for communication and camouflage. Cephalopods have a unique structure called a siphon, which they use for propulsion in water. These animals are characterized by their tentacles, which are equipped with suckers for grasping prey. Cephalopods are also highly intelligent, exhibiting complex behaviors and problem-solving skills. They have a closed circulatory system and are capable of rapid movement, making them effective predators in their marine environments.