This was a costume we made for 7 year old Thomas 2 Halloweens ago. It was made from cardboard boxes, 2 aluminum cans with LEDs for the eyes, foil tape, dryer duct, a Velleman voice changer kit, and a VU meter circuit I slapped together to animate the mouth. Very simple to make, and the response from the other kids was AMAZING! By far the most satisfaction we've ever gotten with the least amount of effort for Halloween. If you have any other questions regarding the build, let me know and I'll hopefully be able to answer them for you.
Finalist in the
Halloween Photos Challenge