Vampire squid
The Vampire Squid is covered entirely in light-producing organs called photophores. The animal has great control over the organs. It is capable of producing disorienting flashes of light for fractions of a second to several minutes in duration. The intensity and size of the photophores can also be varied. Appearing as small white discs, the photophores are larger and more complex at the tips of the arms and at the base of the two fins. They are absent from the underside of the caped arms. Two larger white areas on top of the head were initially believed to be photophores too, but have turned out to be photoreceptors.