Octopuses have hundreds of suckers, each one equipped with its own ganglion with thousands of neurons. These ‘mini-brains’ are interconnected, making for a widely distributed nervous system. That is why a severed octopus arm may crawl on its own and even pick up food.
– Frans de Waal

World Octopus Day is actually the kick-off date for International Cephalopod Days and is an excellent time to celebrate these fantastic sea-going brain-foots. (Cephalopod – Cephalo – Brain, Pod – Foot).