Although Ghost Mushrooms aren’t typically on high demand, not many players farm them. Therefore, there’s usually a shortage of these mushrooms, and most of the time you can set them for a high price. Back in the day, these shrooms were quite difficult to gather, and Maraudon was one of the best places. However, beginning with Cataclysm, a few other good spots for Ghost Mushrooms have appeared. Here’s one of them.
Requirements:
- Minimum level 55;
- Herbalism: 245 skill.
Where to go:
If you play Alliance, take a ship to Theramore Isle, from there fly to Marshal’s Stand or Mossy Pile in Un’Goro Crater, and go to the northern part of Un’Goro, at Fungal Rock (63,16).
If you’re Horde, teleport to Thunder Bluff, from there fly to Marshal’s Stand or Mossy Pile in Un’Goro Crater, and go to the northern part of Un’Goro, at Fungal Rock (63,16).
Or, if you’re going to play with an 85+ character which has the Uldum portal unlocked, simply teleport to Uldum at Ramkahen, and from there fly to Un’Goro and go to Fungal Rock (63,16).
What to do:
Enter the Fungal Rock cave and start gathering Ghost Mushrooms. There are about 10-12 Ghost Mushrooms nodes in the cave, and with a level 65+ character you should be able to gather them all within about 3-4 minutes. It takes about another 3-4 minutes for all the Ghost Mushrooms nodes to respawn. So, while you wait, you might as well grind on the gorillas in the cave. They drop Thick Leather and Rugged Leather in case you also have Skinning.
There’s also a chest that pops inside the cave. I found a nice blue item in it, which sold for 100g.
Loot:
After a 30 minutes Ghost Mushroom gathering session, I got: 
Ghost Mushroom x 93 = 150g/stack = 697g
Blue Item x 1 = 100g
TOTAL: 797g after 30 minutes of gathering.
Note that I didn’t have Skinning as well on my character, and I chose to go AFK while waiting for the Ghost Mushrooms to spawn.
Tips:
Ghost Mushrooms can be milled in Violet Pigments and Ruby Pigments.
They are reagents for 6 Alchemy recipes, but most Alchemist would want 7 Ghost Mushrooms at some point, to craft their Alchemist’s Flask for 300 skill. Therefore, you may choose to sell them in stacks of 7.
In case the mushrooms don’t sell to well, you may consider crafting Invisibility Potions, or Limited Invulnerability Potions. These are awesome potions to use in battlegrounds at low level. You can pull various cool tricks with these potions.
Mining / Herbalism combo works as well for this place. There are a couple of Thorium Veins in the cave and you may as well gather those. Also, while waiting for the shrooms to respawn, you can mine a couple of Thorium Veins in the vicinity of the cave.
This does not seem apply to vanilla versions I’ve seen where the level cap is 60. Some mobs occasionally drop ghost mushrooms, but they do not spawn in the cave itself.