The horrid ratmen infest the underground sewers and catacombs under large cities. They are stealthy and surprise on a 1-4. They can assume any of three forms: human, giant rat, or man-rat. In human or man-rat form, they often arm themselves with swords, but prefer to lure unsuspecting individuals into traps where the victim may be held for ransom or later meals. A wererat may summon 2d6 giant rats and control them. Rumours persist of a city of black wererats on a remote shore; the more fanciful tales suggest the black wererats may have powerful spell casters among their number who can magically affect the phases of the moon.