Angler fish are fairly well known, making cameos in movies like Finding Nemo. They're some of the most frightening looking fish we know of. The females attract prey with a bioluminecent pole dangling in front of their faces.
This particular angler is a Melanocetus, AKA the Black Seadevil, that lives in the deep waters of Monterey Canyon off the coast of California. None have ever been filmed alive at the depths they typically thrive in. Now excuse me while I go pretend I never saw this!