Many cephalopods such as octopuses and squid have amazing control over their skin color and texture, both to hide them from would-be predators AND to give them a leg up (8 legs up?) on their prey.
|Apart from the bright blue eye spot, this octopus is very successfully camouflaged.|
Oh, and to put it to rest: don't worry about the plural of octopus. Strictly speaking it's 'octopodes' because the -pus ending is Greek (as opposed to Latin). Nobody uses that though, so octopi or octopuses is just as good.