This unbelievable octopus
is so ghostly and unusual that it occupies its own family, Vitreledonellidae
. Little is known about this marine animal, but it can be found in tropical and subtropical waters around the world.
Thanks to its transparent skin, scientists know that its optic lobes have unusually long optic nerve stalks, meaning its sense of sight is acute. Your eyesight would have to be pretty good, too, to spot one of these ghosts.