Thankfully, the Dragonfish does not hang out in dark alleys.
But if it did, it would see you coming even in the complete dark. It’s like it has infrared eyes. If you look, just under it’s head it has an organ that can produce it’s own red light in order for it to see through the darkness and to surprise its victims.

dragonfish2To deal with the pressures, the dragon fish has a very minimalized skeleton except for the jaws and other parts used for feeding. They have large, recurved teeth that can either be tightly bound or hinged, allowing them to fall inward while eating, depending on the species. The dragonfish also has a second set of jaws located in the branchial basket, which houses the gills as well as this second set of jaws. The dragonfish has a very odd characteristic in that certain genera of dragonfish are missing the two through seven vertebras in their spine. This has been found to be due to the developmental characteristics of the dragonfish. In most fish, the spine develops from head to tail, but in dragonfish it develops in the opposite direction. These missing vertebras allow the dragonfish to have an increased flexibility in their head, allowing them to eat larger prey. The dragonfish, like other deep-sea predators, have light producing organs called Photophores along their body and on a flesh like extension of the lower jaw called a barbell. These photophores are also found on the pectoral fins. The dragonfish, unlike most fish, has a scaleless body. Their body has a slimy, flesh-like outside very similar to an eel.

Read more about it on Wikipedia!