Check out this showing the flexibility of the octopus invertebrate body. Cepahlolpods are a class of mollusks that includes octopus, squid and nautilus, as well as the extinct ammonites. (They’re the ones that have got big swirly circular shells, not trilobites, the ones that look like underwater woodlice.
They’re considered the most intelligent animals that don’t have backbones (invertebrates). The extent of their intelligence is something that’s strongly disputed by different researchers, but it’s beyond doubt that they have impressive learning and hunting abilities.
Studying their intelligence is something that might one day help us if we were to encounter intelligent aliens. Pretty much all the intelligent animals that humans have studies, tried to teach language to etc. have backbones, and therefore brains and nervous systems fundamentally pretty similar to ours (chimps, great apes, dolphins etc.)
But cephaolopods are completely different from us. Humans and cephaolopods don’t share a common ancestor since way before the Dinosaurs, and as the video shows their physical structure is very different. So understanding their intelligence helps get outside of the mindset of pretty similar animals to ourselves.
One important thing that needs studied is cephalopod communication. They use chromatophores (http://en.wikipedia.org/wiki/Chromatophore). These are little patches where they can use their muscles to use pigments to change the colour of their skin. They use this for camoflage, but also to send messages to each other, especially in the more social species of squid.