The answer is yes you can make one...
I like the idea of friendly plastic above for ease but it's a little opaque and light may not shine through it well. However I dont have a better option really that is affordable. My preference for the body would be to cast it out of something like a clear resin. If you are interested, here is the BEST one
. There are a lot of videos online to help with this.
If I used Friendly plastic I would make a form to mold it over out of something you are comfortable with like clay. If you color the plastic too much, the light that shows through may not be green. If you were going to color it I would use a amber colored nail polish inside the friendly plastic.
For the part I actually know more about, the green light inside is really easy. Use one of these LEDs
which you can power by a couple of coin cell watch batteries. You will need to add a push button to activate it if you don't want it to be on all the time. I like these micro switches.
Hope this helps!