Burger King loves to add Halloween food that's weird colors. You'd think they would have stopped a few years ago when their black bun Whopper turned people's poop green.

The burger chain is releasing a new sandwich on Monday called the Nightmare King. It's a chicken sandwich with bacon and cheese on a green bun. Spooooooky.

The green bun isn't the only thing added to the Halloween spirit. Burger King teamed up with researchers and their study found that people who ate the sandwich had three-and-a-half times more nightmares than normal. No word if those nightmares included color-changing feces.

Check back in a couple weeks when we'll know for sure if this new item has the same effect on people's poop.