The Black Swallower
This bizarre fish, found mostly off the coasts of Niger, is notable for its ability to swallow fish from twice its length up to ten times its length. It does so with the aid of its weirdo stomach that hangs like a blob of extraneous flesh off its otherwise sleek body. They are deep sea dwellers, and first became known to man due to the fact that sometimes its prey cannot be digested before decomposition sets in, releasing gasses that force the Swallower to the ocean surface. In fact, in 2007 a dead Swallower was discovered off Grand Caymen containing a snake mackerel almost four times its own length!