Martian

The term Martian refers to anyone or anything originating on the planet Mars.

In the early 20th century, when many believed that Mars was inhabited, the term was used to "little green men" originating there. The term even became with "extra-terrestrial", as any aliens were assumed to be of Martian decent.

The War of the Worlds featured Martian invaders, who's appearance was said to have a strange horror. . Incredible Tales of Scientific Wonder also featured stories about "men from Mars". 

During the Roswell Incident in July 1947, United States Army Air Corps General Rex Denning referred to the aliens discovered in a crashed flying saucer as "Martians." 

''Similarly, in an alternate timeline in 1944, the Na'kuhl were described as "Martian Nazis." 

When Amelia Earhart was confronted with an Ocampa accompanying the Humans who encountered her in 2371, she assumed that the Humans were trying to trick her into believing that Martians had invaded the Earth. 

Following the colonization of Mars, the term was used to describe the name of the very colony placed there; aptly named the Martian colonies. 

Also see

 * Martian insect