Octopus cyaneus

Living as it does on coral reefs, and hunting by day, O. cyanea is adept at camouflage and not only can change colour frequently, but also can change the patterns on and texture of its skin. One researcher observed it change its appearance 1000 times in seven hours.[3][4] As it moves across the seabed it makes changes in its colouring and appearance to match the substrate beneath.[7] The colour changes are instantaneous and made by chromatophores under direct control of the brain.[8] This octopus sometimes produces a “passing clouds” display when stationary near prey such as a crab; this mimics a dark shadow passing across its surface and may encourage the crab to move incautiously.[9]