Robin Williams was a known gamer and his daughter's namesake is no secret -- Zelda Williams is named for none other than Princess Zelda. He was also a World of Warcraft player. Shortly after his death, Blizzard developers Chadd "Celestalon" Nervigg and Ion "Watcher" Hazzikostas responded to a player petition to honor the actor and comedian in-game. The latest Warlords of Draenor beta build includes Blizzard's tribute in the form of Robin the Entertainer.
Currently, Wowhead has datamined three versions of Robin the Entertainer including a djinn, a human female, and a human male -- nods to Genie of Aladdin, Mrs. Doubtfire, and possibly Mork. The NPCs have yet to be seen in-game, so the nature of these NPCs is currently unknown; they might be found in three different locations, or it could be a single representation of Robin Williams rotating through some of his most beloved roles. It's been theorized that he'll be a replacement for The Burning Crusade's Perry Gatner, a character that performed standup comedy in Shattrath's World's End Tavern.