Vampyroteuthis infernalis is the only known species in the order Vampyromorpha: a rather cryptic sisterorder of the Octopods, joined in the superorder Octopodiformes. They are neither squid nor octopus but are supposed to form some ancient link between the two groups.
Despite the indeed very ominous meaning of its latin name (translating to “The vampire squid from hell” these animals are not to be feared: first of all, they are tiny, with the specimens so far observed not reaching larger than 20 cms or thereabouts, secondly  they are only found far, far below the waves in the deeper parts of the oceans, and last, unlike almost all of their cephalopod relatives they do not hunt and are perfectly satisfied by eating “marine snow” or small particles of this and that that drift down through the massive watercolumn above. The association to vampires is largely due to the fact that the enormous (proportionally largest in the animal kingdom) eyes often appear to glow red, while the web between the eight arms is reminiscent of a large Draculasque cloak. 
The two main features of defense in the cephalopods, changing colour to fade into the background and the emission of ink to create a smoke screen before flight are no use in the persistently dark habitat of the vampire squid. Instead, however, they have other features adapted to their life in obscurity: their bodies are covered in “photophores”, small light producing organs that are closely controlled and the modulation of which allows the vampire squid to confuse, dazzle and disorient predators, while attracting prey. Further, instead of their relatives’ ink sac they have the ability to emit a cloud of GLOWING MUCUS from the tips of their arms, the hanging thick cloud of it probably serving as a “double” when attacked, allowing the squid itself to turns its own lights off and sneaks away in the darkness.

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