Heath Ledger's Joker had many particularities, such as scars on his face that formed a permanent "smile" but how did he get those scars? The audience clearly isn't expected to believe him ...

Ask most people who their favorite Joker ... health and beauty products but when Batman figures out the pattern he switches to gassing the city with giant parade balloons. Compared to that, Heath ...

Until 2008, when director Christopher Nolan and Heath Ledger proved that Joker's transformation ... with a big, clown-like smile. Joker: See, madness, as you know, is like gravity.

Christopher Nolan did not think of Heath Ledger first while looking out for an actor to play 'Joker' in The Dark Knight. Ledger ultimately played the evil character in the 2008 Batman movie.