Many of the funniest World of Warcraft Easter Eggs simply come in the form of a snide quote or name combination that holds a clear pop culture reference.
When you are in the Undercity in the Warrior Quarter you are going to find characters named Edward and Tyler mid-battle against an Abomination while characters named Marla and Chloe linger near by. These name combinations are a quick reference to the film Fight Club.
In Auberdine you are going to meet a crab fisherman that appears as a dwarf. His name is Gubber Bump, a quick reference to Bubba Gump Shrimp in Forrest Gump. He even recites a similar line with “Crabs are the food of the sea. You can boil ‘em, fry ‘em, mash ‘em, roast ‘em."

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Many of these several dozen quote reference World of Warcraft Easter Eggs get a little obscure. On the Finkle’s Skinner from The Beast you can see that there is an inscription that reads “Property of Finkle Einhorn, Grandmaster Adventurer." This is a reference to a couple names from Ace Ventura.
In a similar vein you will notice that the plot points in the story Kurzen's Mystery about Colonel Kurzen are a little familiar. This story is inspired by Heart of Darkness, the book that inspired Apocalypse Now.