December 31st, 2016 marked the 20th anniversary of the Diablo franchise, originally released on December 31st, 1996.
Along with the Darkening of Tristram event slated to take place in Diablo III (including a return to the Cathedral from the original game) Blizzard is including an in-game event for World of Warcraft players to celebrate the occasion as well.
The event is apparently already live on EU realms which means it should be starting soon™ on NA servers as well. Along with a Feat of Strength Achievement it also includes some flavor items to temporarily increase player’s stats during the event, a Horadric Satchel 28 slot bag, and a Twelve-String Guitar toy.
To obtain these items players must track down a Treasure Goblin in various areas throughout the world including the Dalaran Sewers and the end of some instances. The goblin will attempt to make his escape by casting a portal. By killing the goblin players are able to enter the famed but somehow nonexistant Secret Cow Level (located in Duskwood) and slay the Cow King, Diabolic Bovine, and Diabolic Tauren.
Upon killing these foul creatures players will be able to loot the flavor items and discover their uses. One notable effect allows players to create a temporary hearthstone by combining multiple Scrolls of Town Portal with a Blank Diabolic Tome to create a Tome of Town Portal. This is still bound to the same location as your normal hearthstone so it may not be totally useful and probably will be removed at the end of the event but is still a fun flavor item.
The event is anticipated to begin at 12:01AM January 4th and end January 10th at 11:59PM so be sure to enjoy it while it lasts!