13. Ocean Sunfish
Another gargantuan sea creature would be this. The ocean sunfish is known as the heaviest bony fish in the world. It can be found in the tropical to temperate waters in the world and weighs about 247 to 1000 kilograms. They’re the natural predators of jellyfish, and they eat by the bulk to maintain their shape. This extremely huge and heavy fish gets its name from its habit of supposedly sunbathing at the surface of the ocean, also partly to invite the birds to come down and feast on the parasites that are also feasting on this fish. So it’s a kind of “You scratch my back, I’ll scratch yours” kind of thing.