This started as a quick sketch for the Daily Sketch Forum, but things got outta hand
Used a mirror and this one picture I found on internet of the Joker sitting in jail. Practicing facial expressions, hair and light with this one. It took me quite some time to finish it so my cheeck muscles are a bit stiff by now lol

Painted in Painter IX.5, added some noise in GIMP.
I may color it at some point... we'll see...