Our seven year old son loves Lego and wanted to be the Lego Joker this year for Halloween. At first my wife and I thought this would be an impossible costume to pull off, but after some internet research we soon discovered it would not be as hard as what we originally thought.
For this Lego Joker Costume we started with the body. First trying foam board, and soon found that cardboard is much more forgiving and easier to work with. After achieving the basic shape and getting it to fit our son comfortably we made some small adjustments to allow enough movement for trick or treating. Once the torso was hot-glued together my wife painstakingly hand-painted the lapel, tie, flower, and shirt.
The next step was the head. We printed out a photo of the Joker's face we found online then taped it to an 8" concrete form tube I had cut to approximately the size of my sons head. I then used my Dremel tool to cut out the eyes and parts of the mouth for him to see through. My wife finished this by adding the finishing details with a bit of paint.
The legs ended up being the most difficult part and the most uncomfortable to wear. We used the foam board to form boxes for the thigh area and shins. We then secured them with suspenders that went on underneath the cardboard torso. To finish the legs we cut a foam swimming noodle down the center and fastened it to the top of the thigh pieces to form the rounded leg portion of the Lego figures, then hot glued foam squares to the bottom sections to make the feet.
We were more than pleased with the overall results of this Lego Joker Costume and our son was ecstatic. He had the best costume in our neighborhood and at his school.