Ghastly creatures of the night, originating in Arabia, who lurk around places of burial and keep watch for the interment of fresh corpses. They may resemble demons, with fiery eyes and breath, but it seems more likely that they are horrid jelly-like grey creatures which become invisible by standing still, and move in complete silence on large feet which make no impression in the dust. Despite their amorphous bulk they are extremely strong, able to wrench away piles of stone covering a grave, and possessed of sharp fangs so that they may rend corpses apart for a ghoulish feast.

As a precaution against ghouls it is best for funerals to be carried out quickly, quietly, and simply, without any rich display, interment of jewels or money with the deceased, or any other activity likely to arouse ghoulish interest.