We were fortunate to spend a few minutes watching an octopus in a tidepool this afternoon.
It performed some "cephalopod magic"— dramatically changing texture and color.
This is the same octopus, but check out the pointy protuberances everywhere:
And yes, pictured below is the same octopus, but here it has turned itself into a rock, matching the colors and patterns of its surroundings, including patches of coralline algae:
And I couldn't resist including one detail picture. For orientation, the eye of the octopus is in the lower right (the black horizontal slit):