Already great at simply blending in, I wonder at what stage in the grand struggle for survival an animal begins to try to take on the appearance of another living creature.
It's one thing (conceptually speaking) to simply try to look like the blade of seagrass next to you or the substrate under you; it's something else entirely to try to imitate some form of life that (presumably) at some point you've seen swimming nearby. Does this mean that an animal is thinking -- in the abstract, since none's around -- of some fish/snake/echinoderm that it's seen in the past?
And since we're on the topic of octopuses, why is it always eight? Eight arms. There are no species of octopus with more or fewer, are there? Not like starfish, for instance, which have varying numbers of rays. Is there something about eight arms that is just eminently practical -- like the argument that two eyes is logical because it's the minimum number to provide depth perception?
I dunno, I used to love eating octopus but quit after I'd had a lengthy dive encounter with one. Just too smart (and playful) to eat, I concluded. It was so eerie when I looked back and saw that he/she looked just like me. (I made that last part up.)