The lethifold will cover sleepers and give them nightmares in order to feed off of their energy. Lethifolds have become semi famous through the Harry Potter books, but has been documented for more than a thousand years. The lethifold feeds off of fear energy as well as life energy.There are reports of them enshrouding and suffocating people probably in order to feed. They are incredibly common and many of the "ghost videos" that show a sheet like entity are really footage of lethifolds. The best defense against them are the typical defenses against dark creatures. They are especially effected by salt and Hexenspeigel charms.