Trick and treat.

Fanta is meddling in the dark arts this Halloween, horrifying thirsty hellraisers with a creepy new mystery soda flavor — one that turns tongues black.

“[We’ve] got a spooky new mystery flavor that’s hauntingly delicious,” the brand’s website teased. “But be warned, your tastebuds are in for a fright. So, sip if you dare and look in the mirror if you’re in for a scary surprise.”

The tonsil-transforming drink — an ebony-hued, zero-sugar quencher that comes in a 20-ounce bottle decked out with creepy graphics such as a hulking spider and a flying bat — is the newest novelty to debut in the cult soda brand’s “What The Fanta (WTF)?” campaign. 

Launched by parent company Coca-Cola in 2022, the initiative offers limited-edition mystery flavors meant to “fool senses and challenge tastebuds.”

Fans are invited to figure out the flavor of the frightful drink and share their best guesses on social media under the hashtag #WhatTheFanta.

On TikTok, the stamp has amassed over 102.1 million views. There, clips of folks trying to crack the flavor code, and watch their tongues go from pink to black, are going viral. 

Daredevils with a thirst for excitement have, too, taken to X, in attempt to solve the tasty brainteaser — and one guess is becoming berry popular. 

“Halloween WhatTheFanta! Not sure of the flavor, definitely a berry of some sort,” one taster said.

“Total blackberry vibes. Yum,” said another.

“I GOT THE FANTA #whatthefanta !!!!! It is black soda and it stained my tablecloth a bit but it’s good! It’s like grape/berry flavored,” yet another enthused.

Fanta’s dark delight is just one way food and drink brands are seeking to cash in on the lucrative spooky season.

McDonald’s iconic bucket is becoming a seasonal favorite, while Burger King’s famed “Ghost Pepper Whopper” scared up plenty of business last October.