Blue-ringed octopus - three (or perhaps four) octopus species that live in tide pools and coral reefs in the Pacific and Indian Oceans, from Japan to Australia (mainly around southern New South Wales and South Australia). They are recognized as one of the world's most venomous marine animals
Southern blue-ringed octopus Named for the small, iridescent blue spots it develops when alarmed, the southern blue-ringed octopus is one of the world’s deadliest venomous animals. The toxin in its venom is 1,000 times more powerful than cyanide. -
The blue-ringed octopus. This admittedly cool-looking creature is known to hide out in the tiny rock crevices of Australian tide pools and is responsible for more than 20 recorded deaths–mostly of young children who didn’t know any better. Perhaps most frightening is that there is no known anti-venom for its powerful poison. Death generally occurs within two hours.