blue ring octopus - Produce a strong Nero Toxin called Tetrodotoxin. this Octopus uses as a defensively. It also has a Toxin that is Harleysville to humans and is used on its prey. This little fellow is found in Tide poles in semi warm climates.
When they unfold and get out in the open, they are formidable animals indeed: (a diver gets acquainted with one old and wise specimen in the Japan Sea, Primorie, Russia - a Giant Pacific Octopus Doflein).