Portuguese man o' war
Blanket octopodes are immune to the venomous Portuguese man o' war, whose tentacles the male and immature females rip off and use for offensive and defensive purposes. Like many other octopodes, the blanket octopus uses ink to intimidate potential predators. Also, when threatened, the female unfurls her large net-like membranes that spread out and billow in the water, greatly increasing her apparent size.