I have gotten both since MoP launched - I think actually I came back right before ToT opened, is that 5.3? Yea well I really wanted the raptor - best looking raptor ingame no doubt, red and armored? yes please. And I got that after like a few days of farming. But it took about 5-6 months of daily farming to get the panther. And to be honest it seemed like everyone in my guild had it the same way... easier raptor, no panther.