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I found this today while leveling cooking, which I need chilled meat and rhino meat for. I noticed it dropped pretty much meat, almost 1 per kill and some dropped both kind of meats. Anyways, let's start, we are going to kill rhinos in Borean Tundra;
Wooly Rhino Bull - NPC - World of Warcraft
Wooly Rhino Calf - NPC - World of Warcraft
Wooly Rhino Matriarch - NPC - World of Warcraft
Those drop rhino & Chilled meat together with grays & green/blue worlddrops, I managed to get up to 900g~/hour here on my protretri pala. It might be better if you're a mage or something with awesome AoE, you should farm at this spot and loot every rhino, please note that I'm an enchanter and therefore I could disenchant the greenies that dropped. You're mainly after the meat, a stack of rhino meat go for atleast 70g on my server and a stack of chilled all from 50-100g. The reason behind this is that people either level cooking or are doing the cooking dailies.
This place is ideal to farm at, as the rhinos walk together in big groups and respawn relative fast, by the time I killed the last group of rhinos new ones had spawned.