This was a very difficult & fun costume to make. I used things I had around the house. First I cut a laundry basket attached a cardboard ring at the bottom covered it with alum foil added green an blue material inside with battery operated lights covered the whole thing with clear heavy plastic.
I used a pair of suspenders to hold it up on him. Cut a piece of white shimmer material for the beam at the bottom attached blue battery operated lights on the underside to shine on the beam. used a black cloak as his costume attached a piece of color changing dish cloth to the front and painted an alien face on him.