When it comes to disguise, I usually leave it for the octopus because they are the master of disguise but among octopuses, there is a specie that takes camouflaging to another level and that is the Mimic Octopus (Thaumoctopus mimicus). With a size of about 60cm at its max, it is found in the shallow water of the indo-pacific, basically south east Asia. It is smaller compared to the giant pacific octopus but it is a great shape-shifter that can transform beyond what you can imagine.
Camouflaging is something peculiar with a lot of animals as they do to escape being preys, or they use it to predate, they use it to blend to their environment, for mating, and so on but the octopus species is very great at changing colors, shape, and even texture within a short period of time. In the case of the mimic octopus, it doesn't blend with the background, rather it picks the shape of another sea animals or specie. It takes shapes that are daring, causing the predator to be scared of coming close because it had shapeshifted to a poisonous specie or one that is a predator to the animal coming for it.
Researchers have claimed to see the mimic octopus take shapes of mantis shrimps, seahorses, starfish, giant crab, corals, and many more, and they pick these creatures because they are packed with venom and are not often eaten for the fear of death. Scientists have attributed its ability to shape-shift to genetic and environment. Since it lives in the open sandy shallows of the indo-pacific with large bony fishes, sea snakes, and sharks.
There are cases where they mimic the lion fish and since it is very bony and could choke a lot of the sea animals, they avoid it and so it is very quick to shapeshift into it. In other to fully mimic the creature it is shapeshifting into, it learns how they move as its shapeshifted creature does and this is very useful for the octopus because it does often fool the animal coming to have a taste.
https://s3.animalia.bio/animals/photos/full/original/2560px-mimic-octopus-281428065011829.webp
animalia.bio
The Mimic octopus uses its chromatophores specialized cells very well to change colors to the color of the creature they want to mimic. The chromatophores is found just beneath the surface of their skin. The chromatophore skin center has pigments of black, yellow, brown, and orange so when they stretch or shrink each pigment sac, it releases the hue they need to give the color they want.
Coming to texture, the octopus uses the papillae to change texture which can range from bumpy, smooth, rigid like and so on. These creature are able to utilize their cells and characteristics to hide in plain sight or pick the shape of another creature. The mimic octopuses are so good at this that they were only discovered in 1998 and since then, we have just been learning about the creature and there is still a lot that we have not learned. Their ability to evade formal discovery until 1998 shows how impressive they are at mimicry and camouflaging. One of the constraints researchers are having is its lifespan as males will die shortly after mating, and the female will die shortly after laying her eggs.
https://www.nationalgeographic.com/animals/invertebrates/facts/mimic-octopus
https://ocean.si.edu/ocean-life/invertebrates/how-octopuses-and-squids-change-color
https://pubmed.ncbi.nlm.nih.gov/20203250/
https://www.smithsonianmag.com/science-nature/the-mimic-octopus-34059594/
https://www.nature.com/scitable/blog/accumulating-glitches
https://blogs.scientificamerican.com/octopus-chronicles
https://ocean.si.edu/ocean-life/invertebrates/how-octopuses-and-squids-change-color
