There is a secret area in which only the GM's know, where you can make thousands of gold on each NPC without being banned.
"In actuality, there is a small island that is not marked on the map known as GM Island that contains a house. The island is unpopulated. There are no NPC's on the island and there are no portals to any of the cities.
There are children in an attic in Goldshire who perform a demonic ritual if watched at a certain hour of the day, or at a certain time of day leave the attic to go to a secret spot filled with high level items.
What happens is the 6 children go into the attic inside and just stare at the wall and creepy music starts to play. Rumor has it Blizzard added it as a Blair Witch joke and a spooky voice is supposed to play also. The voice is the death scream of Sylvanas Windrunner, the Undead Banshee Queen.
If one yells the classic "Leeroy Jenkins" while attacking someone, the Leeroy Jenkins remix will start playing.
In Molten Core, there is a crack in the wall behind where Golemagg the Incinerator stands. Experienced players taking new players through the Molten Core for the first time would often tell the newbies, "if you jump up in there, you can see Blackwing Lair through the crack."
Actually, the crack has a lava effect inside it, and so players take hit point and durability damage for touching it.