Originally I was hoping to find a full mannequin body locally to use as the "host." Unfortunately I was unable the find anything and all of the online options seemed expensive with shipping.
Luckily, HackPGH had some spare, foam mannequin heads lying around that they let me use for my project. Still in need of a mannequin torso, I found this Instructable which provides instructions on how to make a mannequin of your own body using duct tape casting.
I used an undershirt as my scrap shirt and, because this project doesn't really need an entire mannequin upper body, I stopped duct taping at my navel. I only ended up using a single roll of duct tape, but would recommend more as more layers result in the final product being stiffer.
This is already the creepiest thing I've ever made, by far
The last step for the mannequin was attaching the head to the torso. The fit was already snug so a few strips of duct tape were all that was needed to attach the head.
The wig is something I picked up from Amazon. I'm hoping to style it after Kane's hair from the original movie.