Aliens

The familiar 'gray' can be seen in iconography from many cultures and eras. Earliest descriptions of the modern era include this being or a variation of it with greater regularity than any other.

Drawing of beings seen in the early 1960's by a Kansas resident.

The following "Dance of Death" mural may date to the mid-1400's and there are several mysteries surrounding it and others like it found elsewhere. The symbolism is odd and the meaning may have been obscured by the intrusion of later artists inserting known figures into the "march".  The familiar symbol of the thin, bald, featureless figure is apparent and said to symbolize death but the style appears unique.