Magic mouth spells are used to transmit welcomes, warnings, and messages to visitors. As these magical manifestations exist until they are dispelled, some are very ancient and forgotten. On rare occasions, long after the original spellcaster has died, the mouth gains sentience, becoming self-aware. Aware of its predicament and angry over being forgotten, it becomes vicious and utterly demented-a malignant mouth is born. Malignant mouths are usually found in ancient subterranean vaults, forgotten towers, and abandoned scriptoria (places of loneliness surrounded by ages of dark influences).