Use GRINDBOT This is a simple profile that will farm the trolls in Zul'kunda in Northern Stranglethorn. All mobs in STV now have a chance to drop the Hyacinth Macaw, and these mobs are relatively close together with a good respawn rate. This is also good for farming silk or wool, or grind-leveling (the mobs are 25-27). Fully AFK'able. There is a repair vendor at Nessingwary, but no mailbox added. View attachment [Farm] Hyacinth Macaw - STV Trolls.xml
Well the chance of drop is listed on Wowhead.com as 0.01%, so if you kill 10,000 things one of them should be it. It will be an extremely low drop rate no matter what profile you use. On my server I tried farming it for a few days and then just bought the damn thing on the AH for 12,000g.