Grey

Greys are among the earliest examples of alleged extraterrestrial life believed to exist in human culture. The existence of these beings has been strongly promoted by ufologists and New Age communities and is described in half of all reported alien encounters in the United States. Throughout the late 20th century, Greys have been frequently regarded in popular culture and many paranormal theorists have investigated into possible alien incursions. This has also led to a number of conspiracy theories regarding the purpose behind the Greys' visits to Earth and several hoax encounters between Greys and humans. As yet, no solid proof of Grey's existence has been discovered, but speculation on them continues to this day.

History
An event most often associated with Grey aliens is the Roswell Crash in New Mexico in summer 1947. Details of this event are difficult to tease out from the masses of official and unofficial material on the subject, which tends to extremes of conspiracy theory and of official cover-up. It is very difficult to tell which documents and accounts of this event are real, which are fake and which are just out of context, and range from a theory that the US government was using saucer-shaped weather balloons to test for a surveillance program, only to be foisted by its own radar patard, to the USSR deliberately sending balloons with child-sized dummies in them in an effort to cause hysteria in the US, to actual aliens.

Appearance
Greys have commonly been described as humanoid beings with hairless grey skin (hence the name), standing between 2-4 feet tall, sporting bulbous heads and large black eyes. They have also been frequently described as being thin and frail and never wearing clothing. They have no visible ears or sexual organs, tiny noses and short mouths.

Purposes
If Greys do exist and have truly been visiting Earth, no one knows precisely why. The theories behind their visits are many and range from simple curiosity to more outrageous, even incomprehensible reasons. In many tales of alien encounters, Greys have supposedly abducted human beings and different kinds of animals for experimentation. The suspected reasons behind these experiments include bizarre attempts at communication, genetic tampering (perhaps to determine if Greys can breed with humans or to use Earth life as material for creating biological weaponry), or to determine if Earth life is suitable for them to ingest. Other theories regarding the Greys' observation of Earth include studying humans to determine how threatening we may be and whether or not our planet is worth conquering. The debate of Grey's existence and their plans among modern culture continues and will likely go on until the aliens - if they do exist - finally decide to open communications with humanity.

Trivia

 * In the game, Perfect Dark, Joanna Dark works alongside the Greys (called "Maians") against the Skedar, which look much like Nordic aliens.
 * The Furons of the Destroy All Humans! game series seems to be based, at least in part, on depictions of Greys. Same with the aliens from Fallout 3's Mothership Zeta add-on pack.
 * Greys are featured in the Video game Area 51.
 * According to Paul, the lead character of the movie of the same name and another Grey (his actual species is not stated), his species have been releasing images of themselves to humanity so that when they finally do make first contact, we won't attempt to destroy them in fear.
 * In the video game XCOM: Enemy Unknown and its remake, the first aliens that players encounter - Sectoids - are based on Greys.