The Mariana Trench, located in the Pacific Ocean, is the deepest part of the Earth's oceans, and actually the deepest part of Earth itself. It's no surprise that there are thousands of interesting species living there, and many of them are unique to the Marianas Trench and you'll never see anywhere else.
Hatchetfish are deep-sea fish that are not exclusive to the Mariana Trench, but are still odd-looking. The hatchetfish are special creatures because they are capable of producing their own light, which helps them escape from predators. At those depths, a built-in flashlight is handy to have!
2. Frilled Shark
Frilled sharks are one of the oldest species around and they lurk in the depths of the Mariana Trench. They're hard to spot, which makes them terrifying to prey when they use their snake-like bodies to sneak around.
via Strange Waters
Footballfish are deep-sea anglers that live in the Mariana Trench. They look like a football, thus the name. The lure on the top of their heads is what attracts their prey, which they then quickly snap up with their fierce jaws.
If for some reason you find yourself at the depths of the Mariana Trench, you'll spot the dragonfish thanks to its own bio-luminescence. Their distinctive flashing chin barbell helps lure both prey and potential mates, so beware.