Earth's oceans are home to some truly terrifying creatures.

From predatory sea critters named for land animals, such as the Atlantic wolffish and the rattail, to underwater beings that look truly alien, like the hagfish and the faceless cusk eel, what lives at the bottom of our oceans is entirely otherworldly.

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Creatures that live thousands of feet below the ocean's surface have developed special adaptabilities to survive. While some of them may look strange to us, they've developed these appearances over thousands of years to help them thrive in their extreme environments.

From qualities like bioluminescence, in which creatures produce their own light sources in the dark, to special resistances against the extremely high pressure in the deep sea, these animals have found a way to live in their otherworldly environment.

Some of these incredible photos were taken by an underwater robot operated by the Monterey Bay Aquarium Research Institute (MBARI), giving us a glimpse at these mind-boggling creatures.

This World Oceans Day (June 8), take a look at some of the most unusual looking creatures that have been discovered.