Materials needed:
Fiber Fill (those found in stuffed toys)
LEDs
Button cell battery (CR2032)
a couple of strong little magnets
some paint
To begin, measure the amount of fiber fill needed for your desired effect, here I just painted it yellow and black. There are several techniques out there on how to shape the fiber fill, some use hair spray. I think the paint I used was good enough to stiffen the material. I wanted to depict another small gundam (astray red frame) went through the huge psycho gundam. Shown here is the back portion of the huge gundam.
The batteries would easily attach to the magnets. On this project, I used a total of four individual LEDs.
Here it is with lights off and on
(photo credit goes to Club Gunpla)
The battery lasted about 48 hours.