A pen filled with live parasites might sound like something ripped straight out of a Resident Evil game, but this surreal product isn’t a work of fiction. Social media exploded recently when footage of the pen started generating both fascination and skepticism. Some dismissed the clip as fake or AI-generated nonsense. Yet, Japanese news outlet Asahi News confirmed that the product is, in fact, very real. It’s sold by a fishmonger shop in Susaki City, Japan.

The parasites inside: Anisakis

The star attraction in this peculiar writing utensil is the Anisakis parasite, which naturally resides in marine fish and squids. For humans, consuming raw or undercooked fish containing live Anisakis can lead to a nasty case of food poisoning. Symptoms include abdominal pain, nausea, and vomiting — yet, in the pen, the worms remain sealed and, presumably, harmless.

Tatisuisan, the company behind this strange product, harvests the parasites from fish caught fresh in their region. The pens are only available in limited batches, their production inherently reliant on the supply of infected fish brought in weekly. Talk about a product tied to nature’s unpredictable rhythms.

The origins: Viral inspiration

The idea for the pen came from an older viral video back in 2021. That clip, created by someone named Funa 84, shows Anisakis worms that had been removed from his own stomach being repurposed into a pen. Yes, you read that right — it was a stomach-to-stationery kind of project. This eccentric act captured the imagination of Tatisuisan’s president, who decided to commercialize the concept for an even wider audience.

A cultural and digital phenomenon

While the pens are undeniably rare and niche, their bizarre design has gained traction far beyond Japan. Fans of Capcom’s Resident Evil series were quick to latch on to the eerie visual aesthetic of a writing implement filled with wriggling parasites. Social media users rewrote goofy versions of Resident Evil-style diary entries, imagining a hapless office worker using the pen to jot down mundane tasks, only to accidentally unleash wriggling doom.

One such parody diary reads, “April 9th, I found this cool pen with wriggly stuff in it at the office. But as my manager walked in, I started chewing nervously on it. I also let my dog have a nibble because it tasted funny. Hope the thing inside doesn’t escape. April 10th, it escaped.” Admittedly, it’s an easy leap to connect these pens to horror-centric narratives.

Where oddity meets craftsmanship

Japan is no stranger to quirky niche items, from canned bread to sushi-flavored soda, but this pen stands out because of its tie to natural biology. Unlike many ultra-kitschy novelty products, this one has a certain horrifying authenticity. Anisakis parasites might be revolting to some, but they hold a strange fascination for others due to their peculiar lifecycle and close association with Japanese cuisine like sashimi and sushi.

The entire concept also raises ethical questions — not in terms of harming the parasites, but about the demand driving such a niche product. How much of these pens’ appeal stems from their novelty alone? And does that justify perpetuating a product whose materials come from diseased fish? For fans, the answers are probably less important than the sheer thrill of owning or gifting something so bizarre.

Who would buy a parasite pen?

It’s unclear whether the product is primarily marketed to domestic Japanese buyers or if international enthusiasts have sparked any noticeable demand. What’s certain, though, is how firmly these pens tap into a very specific demographic — people who embrace dark humor, horror, or biological oddities. As collectibles go, they fit neatly into the “weird but cool” category alongside items like taxidermy insects or snake wine bottles.

On the practical side, it’s highly unlikely anyone purchasing the pen uses it for the standard purpose of writing. Its transparent outer shell turning the worms’ squirming on full display makes it decidedly more of a display item than a tool for jotting notes.

Resident Evil parallels that fuel the buzz

Internet buzz elevated the pen’s pop culture relevance, much of it fueled by comparisons to props or items one might stumble across in Resident Evil or other survival horror franchises. The parasite pen, to fans, feels like an object dripping with ominous storytelling potential. Imagining the worms inside slowly coming to life or infecting their surroundings creates an organic bridge between this real-world curiosity and the outlandish, grotesque fiction that fans of these games adore.

This, perhaps, also underscores a broader trend in how physical novelty products thrive online. The pen’s entire identity rests on its strangeness, much like other viral oddities such as Japanese “space ramen” or glow-in-the-dark axolotls in a jar. Its moment in the digital spotlight proves once again that one provocative idea, no matter how niche or unnerving, can capture the global imagination.

Real-world risks

Though no official warnings have surfaced regarding purchases of the parasite pen, there’s always some risk surrounding live organisms. If the pens aren’t sealed properly or the parasites react unpredictably to storage conditions, there could be unintentional exposures. Of course, the manufacturer states that the pens are designed to be safe, but without wide-scale distribution, independent testing of claims like these remains minimal.

In many ways, such risks add another layer to the item’s allure. Collectors who actively look for biologically strange or ethically edgy products often revel in the unease they bring to onlookers. This pen doesn’t just invite curiosity — it almost dares you to imagine worst-case scenarios.

What’s next?

Could bizarre bio-stationery like this pen usher in a new category of weirder-than-ever collectibles? That remains to be seen. For now, the parasite pen’s mystique lies in its fleeting availability and cultural oddity. And though its fame stretches significantly beyond Japan’s borders thanks to viral videos and fan circles, its appeal is ultimately rooted in the marriage of horror storytelling and an undeniable fascination with the macabre.

One thing is certain: whether regarded as a brilliant piece of niche design or an unsettling novelty best left unbought, it’s a product you’re not likely to forget. Too few items tap into both our instincts for curiosity and disgust quite like this writhing worm pen from Susaki City.