Little green men is the stereotypical portrayal of extraterrestrials as little humanoid-like creatures with green skin and sometimes with antennae on their heads. The term is also sometimes used to describe gremlins, mythical creatures known for causing problems in airplanes and mechanical devices. Today, these creatures are more commonly associated with an alleged alien species called greys, whose skin color is described as not green, but grey.
During the reports of flying saucers in the 1950s, the term "little green men" came into popular usage in reference to aliens. In one classic case, the Kelly-Hopkinsville sighting in 1955, two rural Kentucky men described a supposed encounter with metallic-silver, somewhat humanoid-looking aliens no more than 4 feet (1 m) in height. Employing journalistic licence and deviating from the witnesses' accounts, many newspaper articles used the term "little green men" in writing up the story.
Usage of the term clearly predates the 1955 incident, for example, in England reference to little green men or children dates back to the 12th century green children of Woolpit, though exactly when the term was first applied to extraterrestrial aliens has been difficult to pin down. Folklore researcher Chris Aubeck has used electronic searches of old newspapers and found a number of instances dating from around the turn of the 20th century referring to green aliens. Aubeck found one story from 1899 in the Atlanta Constitution about a little, green-skinned alien, in a tale called Green Boy From Hurrah, "Hurrah" being another planet, perhaps Mars. Edgar Rice Burroughs referred to the "green men of Mars" and "green Martian women" in his first 1912 science fiction novel A Princess of Mars, though at 10 to 12 feet tall, they were hardly "little." However, the first use of the specific phrase "little green man" in reference to extraterrestrials that Aubeck found dates to 1908 in the Daily Kennebec Journal (Augusta, Maine), in this case the aliens again being Martians. In 1910 (or 1915), a "little green man" was allegedly captured from his crashed spaceship in Apulia, in south-east Italy.