St. Anthony plagued by shayatin, engraved by Martin Schongauer in the 1480s.
The Shaytan (also Shaidaan), demon, devil, or fiend is a rebellious, malevolent jinni associated with demonic forces who rebelled against God and are, under the service of Iblis. These beings sometimes appear as snakes which can enter a mortal's body.
The original Greek word daimon does not carry the negative connotation initially understood by implementation of the Koine δαιμόνιον (daimonion), and later ascribed to any cognate words sharing the root.
A demon is considered an unclean spirit, an evil jinni, which may cause demonic possession, calling for an exorcism. In Western occultism and Renaissance magic, which grew out of an amalgamation of Greco-Roman magic, Jewish demonology and Christian tradition, a demon is a spiritual entity that may be conjured and controlled.