"Devil" is in the name of this evil looking fish, another one of those deep-sea creatures that, until recently, was unknown.
The Fanfin Seadevil is a species of anglerfish. If you're not familiar with the family, that strange protrusion from the front of this guy's head is actually a lure. The anglerfish uses this lure to, well, lure little fishes right into his mouth.
Unlike other anglerfish, the fanfin lacks the bioluminescent bulb on his lure.
To us, the seadevil looks quite red. And he is red. You would think that would make him a poor hunter, since the fishes that would see the lure would clearly pick out the monstrosity at the end of the line. However, at the depths of the ocean that we find Mister Devil, the wavelength for the color red is very poorly reflected. Therefore, he is essentially invisible.
If it were me, I'd rather not know what my impending death looked like, anyway.