Darkmoon Beast Deck

Now that you have gathered all of the Beast cards together into a deck, a ninth card mysteriously appears with the same backing as the first eight. On this card is inscribed, "Return these cards to the Darkmoon Faire and be rewarded." You have heard that this faire alternately stops at Mulgore and Goldshire every few months, so you will have to wait until they are here next.

Oh dear.

Well this explains a lot. If you ever find a way into Ahn'Qiraj, keep an eye out for ol' Brann. I'm afraid that he'll be powerless without his monkey.