Who's head is in the Joker's 'calling' card?

Question

http://www.yourprops.com/norm-4832131c50c02-Dark+Knight,+The+(2008).jpeg

That was the card Joker gave the mob bosses in the Dark Knight and he said it was his calling card, who's head is it?

Answer 1

It's probably the Kings head in the set or more than likely, no one special. It's just a head.