Black Rat
This NPC can be found in Duskwood (22), Razorfen Downs (28), Scholomance (1), Wetlands (2), Shadowfang Keep (12), Utgarde Pinnacle (2), Utgarde Keep (8), Western Plaguelands (20), Sunwell Plateau (4), Halls of Stone (7), Drak'Tharon Keep (2), Ahn'kahet: The Old Kingdom (5), Violet Hold (3), Icecrown Citadel (13), The Forge of Souls (9), Pit of Saron (8), The Slave Pens (4) and Hellfire Citadel (16).