People who eat Burger King's special black Halloween Whopper have reported a disturbing side-effect.
It turns your poo green.
The Halloween burger, which was launched last week, has proven popular among fans - although many newfound aficionados have voiced their concerns:
Took like three days for my poop to stop being green, but was totally worth it, @BurgerKing— Toasty (@ImHunterStanton) October 5, 2015
Yesterday I had the Halloween Whopper... Today my poop is green. Yesterday was the last time I'll have the Halloween Whopper.— Daniel Rodriguez (@Danny_Seth) October 4, 2015
Incase anyone wanted to know, the Halloween Whopper turns your poop green. And not even sickly green. Like cartoon green. Comical green.— CRU$T DAD (@johnkritzman) September 30, 2015
Others thought the promotional stunt might be more appropriate for St Patrick's Day:
The alternative burgers
The alternative burgers
1/10 Black 'Kuro' burger
Burger King Japan took weird burger mutations to new heights/lows, announcing a Premium Kuro Burger (kuro means "black") with black buns and cheese coloured with bamboo charcoal and squid ink ketchup.
2/10 Red burger
Burger King is now serving up red cheeseburgers in Japan. The Aka Burger ("aka" means "red") comes in two varieties - Samurai Beef and Samurai Chicken, both making use of red cheese and red buns. Tomato powder was added to give the ingredients their angry colour, with the burgers also coming with a red hot sauce made from miso and hot pepper.
3/10 ‘The Glamburger’
A restaurant in Chelsea has found a not-so-novel way to celebrate excess: by claiming to have created the world’s most expensive burger, embellished with gold leaf, lobster and caviar. Priced at £1,100 (or £1237.50 with service), the burger took three weeks to develop and has been verified by Record Setter as the highest priced in the world.
4/10 Doughnut burger
Why use buns when you have doughnuts? You can find these calorific sweet/savoury delights in America, also known as the 'Luther Burger'.
5/10 Ramen burger
Fried ramen noodles replace the traditional bun here, which, when introduced at a Brooklyn food market, sold out in hours.
6/10 Pizza burger
Bringing two of our favourite fast foods together, this burger is cooked inside a pizza, and packs a massive 1,360 calories.
7/10 Lasagna burger
This invention from Philadelphia’s PYT sees deep-fried lasagna replace the buns.
8/10 Holy cow
This special Father's Day dish from Reds True Barbecue in America contained 17 types of beef.
9/10 The Impossible Cheeseburger (Veggie burger)
Don't want to eat meat but enjoy the taste of seared carcass? The Impossible Cheeseburger might be the cheeseburger for you, using plants to make "the best meats and cheeses you’ll ever eat."
10/10 The 'Zinger Double Down King' burger
KFC's new meat beast burger is a bun-less creation with fried chicken acting as buns, released only in Korea so far.
Burger King is yet to release a statement.