These deep sea dwellers are thankfully out of our reach, but just knowing that something this BUTT-UGLY lurks anywhere in the ocean is cause for alarm, as far as we're concerned. The species defining characteristic is a protruding filament that springs from its head that acts as a lure to its prey, and some Angler fish even have a bioluminescent tip. It's mating habits are perhaps the most creepy in all of the animal kingdom. The males, which are dwarves in comparison to the females, bite into the females' skin, releasing an enzyme that fuses their mouths to the female's body. The male NEVER DETACHES ITSELF and merely waits until the female is ready to spawn, after which the male merely withers off the body and dies, thus redefining the idea of being a stalker.