M

Malleus Maleficarum.The Witches Hammer German treatise published in 1487, written by two inquisitors monks, Heinrich Kramer and Jacob Sprenger. It was one of the most radicals texts against witchcraft crimes and methods to use for a trial.  

Mouth: Dangerous, since demons can go through it, so yawning is a bit taboo in some cultures. The soul goes out of the mouth after death. This is why a sick person must be careful not to yawn, since devil could enter and take his soul. It has great relevance in Physiognomy studies.