Like its predecessors, Diablo III is home to numerous easter eggs. The game is clearly a Blizzard title—with which I mean to say that the developers take a lot of creative liberties and have a lot of fun with its content—so players can expect to find all manner of references in the game.
The references and easter eggs range from item names and rare monsters based on Blizzard employees, or ones much larger.
As I've been playing the game pretty much non-stop since its release, I've decided to compile some of the easter eggs I've discovered thus far.
Artists' Names
In the old Tristram Cathedral in Act 1, you can view the names of the game's four principal environment artists—Brian Ameling, Julian Stone, Kevin Choik, and Oliver Christian—chiseled on one of the walls.
Starcraft II's Archon
Players of Starcraft may remember the words "Power Overhwhelming". It wasn't just a cheat code you could enter in single player—it was also a line spoken by the Archon (which was the result of two Protoss Templars combining) in the game.
The Archon is back in Diablo III, this time as a high level ability of the Wizard character class. Although it doesn't require two characters to merge into one (which would be pretty weird if it did) it looks pretty similar to the one in Starcraft and is clearly a reference. Beyond that, it's a pretty neat concept.
The Horadric Hamburger
The Horadric Hamburger is a Legendary item that drops only in the Whimsyshire secret level. As the name suggests, it's a hamburger that you equip in your hands as a weapon. It doesn't deal much damage, but it's amusing nonetheless.
References in the Achievement Names
Achievements play a huge role in Diablo III. Aside from rewarding players with some sense of achievement, they also allow you to unlock stuff to adorn your player flag with.
Many of the titles of these achievements are pop culture references, and one that comes to mind is "Breaking Not So Bad", which is an achievement you get for salvaging an item. It's a reference to the TV show Breaking Bad, if you didn't get that.
Rather than baking bread, it makes me imagine the words "breaking… bad!" in a Hulk voice. Thanks for that, Blizzard.
Squirt
There's an NPC merchant name Squirt who hangs around the Caldeum bazaar. Quite unlike her cousin Wirt in the first Diablo, she's actually a really nice kid, which I suppose is what Wirt used to be before he had his leg torn off by the Butcher. Let's hope she doesn't get a leg chewed off by a demon.
Development Hell
There's a certain dungeon in the game called Development Hell that can be found in Act 1's Cemetery of the Forsaken, amongst the crypts. You can get to it after killing the Skeleton King.
It contains a unique mob named after the game's lead designer, Jay Wilson. Killing him will net you a Feat of Strength, as seen below:
Whimsyshire
Last but not least, there's the the new Secret Cow Level called Whimsyshire. I've written about it here.
Unlike the Secret Cow Level in Diablo II, which featured a large horde of rampaging undead cows, Whimsyshire is a full fledged level with a ton of cartoon-inspired content. Even the treasure chests have been replaced with pots of gold.