This is Harley Quinn, AKA Harleen Quinzel. She was a psychologist at Arkham Asylum where she was assigned to the Joker and fell in love with him. This led to her adopting her own costumed persona, adapting the word harlequin, to assist him escape and cause further mayhem.
I drew it first with pencil in my sketchbook, then I scanned it in to my computer and colored it in Photoshop.
For the background I used a Rust texture by ~awjay (
) here: [link]