Greater Blue-ringed Octopus - Hapalochlaena lunulata
Small sized Octopus, usually the body is less than 10 cm in size. This Blue-ringed Octopus is one of the most venomous animal in the world, with enough venom to 'kill' more than 20 adults. However, they are non-aggressive and not likely to bite or attack humans. They used the venom to paralyse their preys, mostly crustaceans like crabs and shrimps which have sharp claws and pincers, otherwise the crustaceans could easily inflict some damages to the Octopus if they are not instantly paralysed. When at rest, they do not show/flare their blue rings. The 'blue' becomes more intense when it is moving/hunting or under stress, probably as a warning.
The greater blue-ringed octopus is one of four species of venomous blue-ringed octopuses belonging to the octopodidae family.