(n.) One that prowls.

body snatcher booster chicken thief con man crook den of thieves embezzler filcher ganef ghoul grafter grave robber jewel thief land pirate land shark land-grabber larcener larcenist lifter peculator petty thief pilferer poacher purloiner robber scrounger shoplifter sneak thief stealer swindler thief white-collar thief