I don't believe this has come up before...
This is Teuthowenia Pellucida, AKA the glass squid. It lives at tremendous depths in the southern hemisphere, and like many deep-sea creatures, it has light organs. Specifically, around it's eyes. Moreover, if scared or threatened it will puff itself up into a ball by sucking in water, tuck in it's head and tentacles, and then finally fills it's own body with ink so it vanishes in the dark. Clever little mite.
Wiki article here:
en.wikipedia.org/wiki/Glass_squid And another northern hemisphere type here:
news.nationalgeographic.com/news/2007/08/photogalleries/sea-creatures/photo3.html