If you think that picture makes it hard to figure out what's going on with this creature, you're right. You'll find that all photos of it have the same problem.
Sharing its name with an anti-terrorist unit led by Louis Gossett, Jr., the wolf-trap angler fish is also known as a wonderfish, which sounds more like a Saturday morning cartoon show.
They are distinctive because, for one, they have a fishing pole glued to their head. To catch fish, not wolves as their name would imply (if such a fish existed, you'd have fucking heard about it by now). They're called a "wolf-trap" because their massive upper jaws (which are up to three times the size of the lower jaw) have "movable premaxilaries," which means it opens and closes sideways like... well, like a wolf trap.
