The race of aliens said to be commonly seen by people who claim to have seen or been abducted.
There are a number of theories of who they are:
.Some say they are dolphins in the future or past (inhabitants of Atlantis)
.They are our future selves coming back to save us from catastrophe or to get sperm and ovules to mix their race with ours because they are all clones.
.Some say they are co-operating with the US government to trade advanced technology for usage of humans for experimentation. eg. B2-bomber , Stealth Bomber. They just sprung up from nowhere.
The Greys made the stealth bomber.
I got abducted by the greys and they stole my sperm.