Yep. It's made of duct tape.
The front is made out of a flimsy mask from a Boba Fett Halloween costume. It was pretty bad. I only got it because it was 75% off. I just covered it with tape to both strengthen and color it. The back presented more of a challenge though.
I just took a piece of printer paper and covered it in tape. Once it had some durability, I taped it to either end of the mask. The back half of the dome is only tape. I put a bunch of strips connecting the paper to the top of the mask, then put tape on the inside to finish it. Of course, I put a bunch of layers until it was relatively solid.
To finish off, I just covered the inside with tape.
It's an executioner style of helmet. Here's the inspiration:
Lastly, here's a video of it:
It's super cheap and flimsy, but it does its job. And hey, it's made of the most durable stuff on earth