The character is historically composed of 儿 "legs", 田 representing a large demon's head and a curl looking similar to 厶 taken to represent a swirl of vapour, or a demon's tail.
The character can be traced to the oracle bone script, where it depicts a man kneeling on a monster head.
Most of the characters derived from the radical have meanings related to ghosts or souls, including 魔 "devil, demon", 魑 "black magic", 魘 "nightmare", 魄 "soul". In some signs, however, the radical is present purely as a phonetic marker, for example in 魏, the State of Wei during the Spring and Autumn period.
Fazzioli, Edoardo. Chinese calligraphy : from pictograph to ideogram : the history of 214 essential Chinese/Japanese characters. calligraphy by Rebecca Hon Ko. New York: Abbeville Press. ISBN0-89659-774-1.
Childs-Johnson, Elizabeth (江伊莉), 甲骨文的“鬼”与假面具 (The Gui-Spirit in Oracle Bone Inscriptions), International Conference Celebrating the 95th Anniversary of the Discovery of Oracle Bone Inscriptions", Anyang, China, 1994.