Grey-skinned and glassy-eyed aliens you’ll most often see on the silver screen, which is surprising because by most accounts they’re hideous. It is thought that they reproduce via cloning, which is causing them to fade. Their mission on Earth is to create a Grey-human hybrid that can reproduce sexually, and thus perpetuate the existence of their species. Greys, make up 43% of all reported alien interactions. They are reported to be short and sexless beings are almost always naked with big heads and large dark eyes.