Okay, so a grouper and a shark are hanging out near each other in the ocean. Then one of them SWALLOWS THE OTHER ONE WHOLE.
You're probably assuming it was the shark who devoured the fish, because that's a completely natural thing to assume, but in fact, it was the other way around. This video captures a goliath grouper eating a black tip shark (in one bite!) off the coast of Bonita Springs, Florida, according to the video description.
In conclusion: fish are terrifying, the ocean is terrifying, everything is horrible and nobody is safe. The end.