If you were a deep sea fish, you'd likely want to avoid the black swallower at all costs.
Although this creature is relatively small, with a maximum length of 25 cm, the black swallower stands out for its unearthly ability to swallow fish whole that are over two times its length and 10 times its mass. The black swallower is able to accomplish this because of its extremely distensible stomach and wide jaws.
Black swallowers have been found dead from having eaten too large of a meal. They often swallow fish so large, that the fish begin to decompose inside of them before digestion is complete, leading to a release of gasses that sends the black swallower adrift to the ocean's surface.
I can't stop looking at photos of the black swallower's giant, translucent, egg-sack-like belly filled with the unfortunate critters who crossed its path.