The design is original and was made by hand-sketching on the pumpkin with sharpy and then erasing it with whiteboard-erase spray when I was done carving (a new trick I learned while doing this--it takes out permanent marker like a charm!) The pumpkin took 3 straight hours to carve.
Though some of the photos were cropped, no other retouching was done in post processing. The cool color effects are all a result of using a combination of remote flashes, lighting reflectors, and blue gels for some of the photos. Some of the illuminated photos use a standard candle as a light source, and others use a remote flash inside the pumpkin itself. The flash-inside-the-pumpkin experiment turned out to have a really nice effect, and helped to avoid the blurriness that typically is a problem when photographing fire because the light was steady and so bright that the exposure time could be much shorter.