The only way I can see either "giant demon/creature" effect being pulled off is if they used it as the maze façade/entrance... similar to something like this..
speaking of façades, I still can't believe Murdy's crap excuse for not recreating the mansion exterior for Crimson Peak's façade. "Oh if it was scaled down, it would look like a dollhouse"... Has he not heard of "forced perspective"? -_- So I'm curious to see what they do instead for that...