Here is our Pepper's FCG.  He is a Boris head, Bucky arms, a wire frame and a brightner soaked cheese cloth shroud.  He is fairly heavy, so he is also counterweighted.  A normal FCG mechanism has no problem moving him. 

  The reflective surface is a sheet of Plexiglas that extends from wall to wall, floor to ceiling.

  He is lit with a black light, so light bleed into the "hallway" is low.  I put a stone gothic arch stained glass window at the end of the hallway to emphasize that he is transparent, back lit with lightning flashes with thunder.

  He moves his jaw to a digital recorded message played through a big amp and speeker.  The sound reflects off the Plexiglas just like the light.