Octopus skin contains a light-sensitive pigment found in eyes (theguardian.com)

According to Wikipedia, "an octopus has a highly complex nervous system, only part of which is localized in its brain. Two-thirds of an octopus's neurons are found in the nerve cords of its arms, which have limited functional autonomy".

This and the link makes me think that octopuses are one of nature's best distributed systems.