Barbara Kline, a mother-of-two, reportedly suffered sickness and diarrhoea for days after finding a slimy, mystery mass in a bottle of coconut water.
The nurse from Goshen, New York, posted a picture of the stomach-churning discovery on Facebook and said she had accidentally swallowed some.
"I still can't believe this I'm so disgusted it's the only water I ever drink I will never in my life drink it again ... It looks like a freaking octopus just looking at it makes me sick," she wrote in the furious caption.
It's certainly enough to put you off your lunch, but it seems no-one actually knows what the lumpy grey thing is.
"I've got told it looks like a mouse, I got told it looks like a squid, I got told it looks like a bunch of things - that's why I would like for somebody to get it tested for me that has more authority than me," The Sun reported her as saying.
Ms Kline told the media Vita Coco's Pure Coconut water was her favourite drink before the incident on April 25.
She kept the drink in the fridge until she opened it, and said once she tasted something vile, she dumped the rest of the drink and opened the packet with a knife.
"There were four of them all together, maybe five and I swallowed one of them.
"I understand that products get mouldy and products get mispackaged and sometimes spoil but this is just too much for me.
"It was only when I unknowingly swallowed one of those clumps I realised it tasted awful I started vomiting. The diarrhoea honestly just stopped on Friday."
She now sent a clump of the object, along with a note from her doctor explaining her illness, to the company in a bid to demand answers.
She also kept part of it for herself, to have it independently examined.
A spokesman for Vita Coco said they are investigating, The Sun reported.
"We take all consumer inquiries and product quality issues very seriously, and as a global brand have protocols to properly investigate quality inquiries.
"Vita Coco employs the highest standards of food safety at all its production facilities and our beverages are quality- and food safety-tested internally, and also by an external quality control specialist, before being distributed.
"However, because Vita Coco beverages do not contain preservatives, on rare occasion, random spoilage may occur.
"This is what we are investigating now."