Now this is truly terrifying!

Burger King recently unveiled a black Whopper for Halloween, a version of the chain's signature sandwich served on a dark bun. But people who it are having some interesting side effects. People are saying it goes in one color... and comes out another and that color is better suited for St. Patrick's Day.

People are taking to the internet with the hashtag #GreenPoop and one customer decided to post a YouTube video on the subject.