Built the "vehicle mode" of Optimus Prime for my son so he could Transform. It is made out of cardboard boxes, cardboard tubes, cans, dixie cups, a filter for the grill and paint can lids. I used a small strand of battery operated Christmas lights to make the small lights up on the top light up. The headlights were the LED battery operated lights that you get to put up under your kitchen cabinets or in dark places in closets.
When he was walking from house to house he looked like the "robot" mode of Optimus Prime, he wore his toy helmet. Then at every door... he felt he HAD to transform. We he must have done it 100 times between trick-or-treating and the community trunk-or-treat we go to. It was a show stopper... even had some adults asking him to do it over and over as they showed their friends and then video taped it on their iphones.
Sadly I don't have a video of it myself as I had my hands full with my daughter. But here is a link to one on Facebook. My friend had taken it. https://www.facebook.com/album.php?aid=21577&id=1428827147&saved#!/video/video.php?v=107044832640571
He loved it and had such a blast.