Its Friday omg!
This is in the most recent Raid Dungeon. When clearing to the first boss, you can see right down the hall to him. And the first boss is made
made entirely of bone. So the joke here is that the hunter sends in his pet targetting something different, but he sees Lord Marrowgar and his doggie instincts take over. "Bonestorm" is something Marrowgar yells when you fight him. Yeah, this ones a "you gotta play WoW joke" sorry! :P