Go to Townlong Steppes and the island Shanze'Dao, exactly where i am on this screenshot: http://i.imgur.com/x8mZr.jpg
Here you will find two types of mobs;
Shan'ze Illusionist who spawns several images of itself, all of which gives rep when killed, kill the images FIRST as they despawn when you kill the big guy.
Bronze Quilen in packs of 5.
Put down your guild standard and farm away!