But this image is much better (from Mel Gibson's 'The Passion'), he's a sly lurker, reading peoples minds so that he can pick up on their thoughts and make them flare up, he even tried it with Jesus's mate-
Jesus said to Peter - "Satan wanted to sift you" (Luke 22:31)
According to Christianity, the embodiment of pure evil ( powers and principalities ). A willful, prideful spirit who is father of all lies. One who possesses such narcissism as to set up the human race for failure in order to win a bet.