Do you know ? The Camouflage
The octopus is an eight-armed hunter. It uses a most interesting method of concealing itself from other animals: camouflage. The cells which make up its skin automatically adapt to its surroundings and replicate, just like a mirror, their color and texture.

The octopus' eyes are very sharp. It can identify changes in its surroundings most effectively, and thus changes the color and pattern of its skin in accordance with its surroundings. Its skin is covered in special pigment-containing cells known as “chromatophores.” These cells in the skin expand or shrink when stimulated by the nervous system, creating color patterns that can be changed instantly. Different cells carry different color pigments and these allow countless color combinations and patterns to form.