Anyone have any further news on what this 'exclusive' card consists of ?
I enquired with Potomac, who just got back to me with the following :
"Hi Colin
You get one exclusive card per tin. I believe it is a regular card and
not a costume or prop card. Here is the exact text from Artbox:
Each collectible tin features high-quality full-color graphics on the
outside, and inside each tin you will find a great assortment of Harry
Potter trading card foil packs. The Harry Potter and the Prisoner of
AzkabanT collectible tin will have 4 foil retail packs and 1 exclusive
trading card inside each tin. The exclusive trading card inside each tin
cannot be found anywhere else. Be a part of Harry Potter and join this
magical journey that has captured hearts and imaginations all over the
world!
So I'm none the wiser really

Any ideas anyone ?
CJD