Editor's note: The below contains spoilers for Alien: Earth Episode 4. When Ridley Scott's Prometheus came out in 2012, many fans were disappointed by the lack of xenomorphs. Scott aimed to fix that ...

The ocean covers more than 70% of our planet’s surface, yet we’ve explored less than 5% of it. Below the sunlit waves lies an alien world of crushing pressure, eternal darkness, and bone-chilling cold ...

They are iridescent, bright blue and jellylike, with stinging tentacles that dangle from their flat, oval-shaped bodies. Just 3 to 4 inches long, these alien-looking creatures use a short, clear flap ...