Ghouls are a variety of monster that come from Arab folklore. The English word comes from Arabic al ghûl.
The Arabian ghoul is a desert-dwelling, shapeshifting demon that can transform itself into the guise of an animal, especially a hyæna. It robs graves and feeds on the flesh of the dead, or on young children. They also lure travellers into the desert wastes to slay and devour them.
The star Algol is also named after this creature from Arabian legend.