Turns out, there may be an unintentional trick to Burger King’s new Halloween treat.
The Halloween Whopper, a limited-edition burger available throughout the month of October, comes with a black bun to make it extra spooky.
The burger is advertised as having A1 sauce baked into the bun for extra flavor. Unfortunately, customers are saying that some ingredient in the black bun is turning their poop a vivid green color — which is causing some people to freak out a little.
Because it’s like … really green.
Some people have even (unfortunately) taken to posting photos of their brightly colored bowel movements to prove their point. Feel free to take a look — at your own risk — below.
And while the bizarre side-effect has some customers seeing red (and green) …
… some customers are willing to endure mossy stool for a shot at the Halloween Whopper.