Octopuses have no shell to hide in, so camouflage is their defense. We see one rapidly changing its color and texture.
Molluscs: Octopus Camouflage
Next Generation Science Standards for this Video
An octopus is very good at processing information from its environment so it can camouflage itself. It has excellent eyesight and an elaborate nervous system connected to chromatophores in its skin. The skin itself can change its texture and the chromatophores change the skin’s color to match the environment.