of Sant'Apollinare Nuovo. The mosaic "Christ the Good Sheppard" features a blue-violet angel at the left hand side of Christ behind three goats; opposite to a red angel on the right hand side and in front of sheep. Depictions of the devil became more common in the ninth century, where he is shown with cloven hooves, hairy legs, the tail of a goat, pointed ears, a beard, a flat nose, and a set of horns. Satan may have first become associated with goats through the Parable of the Sheep and the Goats, recorded in , in which Jesus separates sheep (representing the saved) from goats (representing the damned); the damned are thrown into an "everlasting fire" along with Satan and his angels. Medieval Christians were known to adapt previously existing pagan iconography to suit depictions of Christian figures. Much of Satan's traditional iconography in Christianity appears to be derived from Pan, a rustic, goat-legged fertility god in ancient Greek religion. Early Christian writers such as Saint Jerome equated the Greek satyrs and the Roman fauns, whom Pan resembled, with demons. The Devil's pitchfork appears to have been adapted from the trident wielded by the Greek god Poseidon and Satan's flame-like hair seems to have originated from the Egyptian god Bes. By the High Middle Ages, Satan and devils appear in all works of Christian art: in paintings, sculptures, and on cathedrals. Satan is usually depicted naked, but his genitals are rarely shown and are often covered by animal furs. The goat-like portrayal of Satan was especially closely associated with him in his role as the object of worship by sorcerers and as the incubus, a demon believed to rape human women in their sleep. Italian frescoes from the late Middle Ages onward frequently show Satan chained in Hell, feeding on the bodies of the perpetually damned. These frescoes are early enough to have inspired Dante's portrayal in his Inferno. As the serpent in the Garden of Eden, Satan is often shown as a snake with arms and legs as well the head and full-breasted upper torso of a woman. Satan and his demons could take any form in medieval art, but, when appearing in their true form, they were often shown as short, hairy, black-skinned humanoids with clawed and bird feet and extra faces on their chests, bellies, genitals, buttocks, and tails. The modern popular culture image of Satan as