A Sludge Demon cannot die, which is one of the highest advantages of a Fiend becoming such a thing. They do however, have very weak defenses and weak strengths, as they are predominantly made of sludge. However, if one is not aware, a Sludge Demon is perfectly capable of swallowing and digesting a living creature before they can fully fight back. Like Ghouls, they often get things sticking to them, often forgotten undigested bits of food. The only way to actually kill a Sludge Demon, is with another Sludge Demon absorbing them, and making a singular entity of the two combined, making a far more powerful Sludge Demon. The more powerful Sludge Demons often consist of thousands of other Sludge Demons, and are the size of cities, if not bigger. It should be noted, however, that Aecliress, the Dream Eater, is not a Sludge Demon, despite it looking very much like one.