The Tremoctopus, also known as the blanket octopus, is a species of cephalopods that inhabits the surface and mid-water of subtropical and tropical oceans. They are best known for the long transparent webs that connect the dorsal and dorsolateral arms of adult females.
They exhibit an extreme degree of sexual dimorphism. Females can reach 2m in length, while males are at most a few centimeters long. Because of this smaller size, males (and also young females) have to resort to interesting defensive techniques.
Particularly, they are immune to the poison of the Portuguese man o’ war. They rip off it's tentacles and use it as a deadly defensive weapon. By contrast, the females are able to spread out their membranes and appear much larger than it actually is.