How voodoo dolls are always depicted as a one-way relationship. Things done to the doll happen to the person, but not vice versa. There's probably potential in that, and not just porn-related ideas. That'd probably be useful for like theme park Mascots, so someone doesn't have to be in that hot-ass suit on a summer day.

Alternatively, I could just put someone "in" a fat cow suit and fuck it / them. Maybe that's just something people do to spice up the bedroom, cuz it's not like it needs to be a suit. You could be a doll when you want sizeplay shenanigans.