This is the Alien Blaster from Fallout 4. This can be found when a spaceship comes crashing down. All you need to do is find the site. Follow the goo and kill the alien and take his blaster. its got space for dowels to help align the parts.
 

I've hollowed the model to fit LED lights. the idea is you print it in clear and paint over the areas where light should not show through. 
 

For a how to guide on printing this bad boy check out the 3D printing nerds video on it! Its a bit aged but I'm aiming to make a new video soon!