Megaleledone setebos, the giant Antarctic octopus, is a very large venomous octopus with a circum-Antarctic distribution. It grows to at least 28 cm in mantle length and 90 cm in total length.[1] M. setebos feeds by drilling small holes in large, shelled mollusks, and then injecting its toxic saliva. The venom even works at subfreezing temperatures.[2]
This species was transferred to the genus Megaleledone and synonymised with Megaleledone senoi in a 2003 paper.