Cepho fact #04

The common octopus has about 500 million neurons, but interestingly, about two thirds of those are found in their arms. This gives their arms somewhat of a mind of their own.

Cepho fact #03

Cephalopods (class Cephalopoda) can be subcategorized into 3 subclasses; Nautiloidea (Nautilus), Coleoidea (which contains all shell-less cephalopods), and the extinct Ammonoidea (Ammonites).

http://eprints.cmfri.org.in/10414/1/09_V._Venkatesan1.pdf

Cepho fact #02

The vampire squid (Vampyroteuthis infernalis, aka "Vampire squid from hell") is actually more closely related to octopi than it is to squid.

Cepho fact #01

Cephalopods use small organs called Chromatophores to change colours. Chromatophores contain small sacs of pigments, when the muscles surrounding the chromatophores stretch, they cause the pigment to expand under the skin and make the colour visible.