Very nice work! I loved that episode, it really gave me the creeps and I'm sure that if I saw your costume in person I would have gotten creeped out too. To really help sell the illusion you should try to find a way to blend the mask into your neck, then people would really have a hard time figuring out if you were a person or a statue.
You should wear that out for Halloween. Stand outside in front of your house nice and still and see how many people you could scare. I can only imagine the passers by commenting on the statue in front of your house and what not and then see them jump like 10' in the air when you move. Even freakier would be if you could get away with changing poses every time they turn away and look back just like in the episode, now that would probably really freak people out.