The mystery of the dragon in Ahn'Qiraj
Some things were added to Patch 5.3 that we don't have an explanation for yet, and one of those things is Andrestrasz, a level 5 red dragon sleeping in a cave on the coast behind Ahn'Qiraj, the Fallen Kingdom on the edge of the Kalimdor continent. To reach him, simply fly over AQ to the coast and follow a copse of trees until you find his cave, wherein he sleeps... and does nothing at all as far as I could tell. There's already multiple pages of speculation about him, but as of yet, I've found absolutely nothing out about the guy.
Who is Andrestrasz? Why is he sleeping in a cave behind AQ? Why is he level five in a zone that's completely deserted and surrounded by zones (Silithus, Un'Goro, Tanaris, Uldum) that are all much higher level? I have no idea, but patch 5.3 brought him in, so maybe we'll see more of him in future content.