A swirling, bubbling, ambulatory glob of blood the size of a hogshead cask lurches forward. Native to a lake of churning blood on an abyssal plane, blood elementals aren’t typical elementals.   Blood mages seem able to retain tiny blood elementals as familiars or guardians of some kind, though the exact nature of their bond is a mystery they guard jealously. Many small sects of blood cultists seem to learn the secret, leading some savants to believe that this knowledge is freely shared by priests of Marena and similar dark gods.   Drawn to Life. A blood elemental is drawn to movement and absorbs whatever living creatures it finds, increasing its size and power in the process. Though feeding is not necessary to sustain themselves, blood elementals, over time, will shrink unless they consume living creatures. However, their need for prey is relatively slight-once a week to maintain their size.   Blood Summoning. Offerings of blood and blood magic spells draw blood elementals from their planar homes, with the proper ritual. They also sometimes follow in the wake of certain demons and devils, devouring entire bodies in a matter of hours.   Elemental Nature. The blood elemental doesn’t require air, food, drink, or sleep.