Black Rat
This NPC can be found in Razorfen Downs (28), Duskwood (22), Western Plaguelands (20), Icecrown Citadel (25), The Forge of Souls (9), Halls of Stone (7), Shadowfang Keep (12), Utgarde Keep (18), Utgarde Pinnacle (7), Ahn'kahet: The Old Kingdom (5), The Sunwell (4), Coilfang: The Slave Pens (4), Violet Hold (3), Drak'Tharon Keep (4) and Scholomance (1).