The blogger responsible for Booturtle made a fairy princess costume for her daughter and added in a bit of the dark side:
Princess Fierce brought me a broken toy crown that I took apart, painted green, added purple glitter sparkles and mounted to the mask. I redesigned the straps to the mask to be purple and green ribbon from the sides and one piece with loops across the top. Allowing me to tie a bow through the loop and basically make a net that sat on her head. She was ecsatic. The mask wasn't too tight but yet did not slip. She wore it comfortably for most of 8 hours.
The tip of her wand is shaped like a Death Star.
Link via Geekologie