The black swallower is a small fish, known for swallowing fish larger than itself. It swallows prey up to 10 times its mass and 4 times its length.
Their stomach is very distensible and the jaws can swing down to open wide, which allows the black swallower to feed on larger fish. The swallower seizes prey fishes by the tail, and then “walks” its jaws over the prey until it is fully coiled inside the stomach.
Sometimes, the prey is so big that the stomach of the swallower can’t digest it. The prey then decomposes and produces gases which fill up the stomach and kill the swallower. Another known cause of swallower’s death is torn stomach (surprise!). Relatively large prey can cut the swallower’s stomach, which causes the swallower to die.
The learning: With great power comes great responsibility.
via Factoroom.ru and Wikipedia.org