Help! I’m trying to figure out how this was made. Obviously, you wear the pants and the box has a hole cut into the side for the top of your body to come through. The box is attached to a fake ‘body’ made from what though? Foam? Newspaper? Something else lightweight? This looks so awesome, except for the fact you’ll have to kinda lean over when wearing. If you have suggestions of how to make this costume, please comment below. All ideas appreciated!
Do It And How 
Find an old hiker’s backpack that includes a built-in frame, fill and pad it out with foam or stuffing material, strap and glue the box to the front with a cut-out that matches with lower-front opening in the shirt and pants. Ideally, it looks like you’ll want to be leaning out from the fly opening in the tall pants.
If you loosen the shoulder straps, the pack should naturally lean back and “separate” from you-in-the-box.
Not certain if that’s how this dude did it but it’s how I’d approach it. Hope that helps some.
Thanks for the great suggestions! Love the ‘you-in-the-box’ term!!
Also, dude looks good in the pic leaning forward in the box but you shouldn’t need to do that all the time. With the right acting, headless dude should just look like he was leaning back with a heavy load if you straightened up.
A pillow between the frame and your lower back is probably a good bet too but other than that play-act in front of a mirror for a while to make your movements in the box match what zombie holding the box is doing and you can probably figure out all sorts of gags you can do for a night of laughs.
He’s thinking outside the box.
Wow! That looks very horrible, awesome for me like your idea.