Masters of disguise
Octopuses can change their skin color and texture to camouflage itself or spray ink if its scared. Some octopuses can sometimes mimic to look like a dangerous creature. They know what to change to by just looking at it. They also remember the texture and color for a long time. Octopuses have special cells called chromatophores below the skin that change to give the octopus it's camouflage. These chromatophores are like balloons. If you squeeze a dye filled balloon it would push the dye to the top to make it appear lighter, It works the same with chormatophores.
Octopus camouflage (better image/sound w/link).