If you need to level up your Halloween look at the last minute, Fanta has got you covered. As Eat This, Not That reports, the soda brand has a released a limited-edition flavor for the fall season with a spooky side effect. Though we don’t know what the special Halloween Fanta is supposed to taste like, we do know it turns drinkers’ mouths a shade of black that makes them look like they crawled out of a horror movie.

Fanta is keeping the flavor of its midnight-black beverage a mystery on purpose. To figure it out, customers will have to purchase a bottle and sample it for themselves. As long as the special soda is available, the brand is inviting fans to guess the flavor on social media through weekly events. The promotion is part of their “What the Fanta” campaign, which debuted last year with a blue mystery drink that was later revealed to taste like raspberry and litchi.

The latest product in the “What the Fanta” line comes with a seasonal twist. After a few swigs of it, drinkers will discover their tongue is as black as the contents of the bottle. Normally that wouldn’t be a selling point, but it feels appropriate in the weeks leading up to Halloween.

The Halloween mystery Fanta is now available in stores, but it won’t stick around forever. To get yours before it disappears from shelves, you can find a retailer selling it near you on Fanta’s website. If you’re baffled by what you taste, you can scan the QR code on the container to participate in an interactive “What the Fanta” experience online.

[h/t Eat This, Not That]

This article was originally published on www.mentalfloss.com as Fanta Releases Mystery Flavor for Halloween That Turns Your Mouth Black.