Camouflage using chromatophores is particularly ... Papillae are sections of the skin that can be deformed in order to change texture, and may work by a hydrostatic mechanism (Allen et al., ...

In MGS4, Old Snake could just lean against almost any wall and absorb the texture via his nifty OctoCamo which, it turns out, was inspired by the natural camouflage abilities of real-life octopi.