Rat
This NPC can be found in Tirisfal Glades (76), Howling Fjord (71), Naxxramas (100), Terokkar Forest (47), Desolace (31), Arathi Highlands (28), Stormwind City (26), Ghostlands (25), Nagrand (22), The Culling of Stratholme (21), Bloodmyst Isle (18), Western Plaguelands (11), Silverpine Forest (10), Shattrath City (9), Stonetalon Mountains (7), Grizzly Hills (6), Hillsbrad Foothills (4), Azuremyst Isle (3), Alterac Mountains (3), Undercity (2), Dalaran (2), Drak'Tharon Keep (2), Stranglethorn Vale (2) and Violet Hold (1).