A pen that writes like any other should not make your stomach turn, but this one does exactly that. A transparent ballpoint pen from Japan has taken over social media feeds because it contains something most people never expect to see: real, living parasites swimming inside. It sounds fake at first glance, yet it is very real and already selling out as a strange souvenir.
This Japanese pen is currently going viral for containing a REAL parasitic worm living in herbal oil pic.twitter.com/5DFZWFvpvk
— Crime Net (@TRIGGERHAPPYV1) April 7, 2026
This unusual product comes from Susaki city in Kochi Prefecture, where a local fish shop decided to turn something unsettling into a talking point. The idea started as a joke online, then turned into a physical item people can buy. What makes it so hard to ignore is not just the look, but the fact that the organisms inside were once alive in freshly caught fish.
What’s Actually Inside the Pen?
AI News / IG / The ballpoint pen holds Anisakis, a type of parasitic worm commonly found in marine fish like bonito and skipjack.
These worms are known in Japan, especially among people who eat raw seafood, because they can cause illness if consumed. In the pen, they are suspended in a clear liquid that keeps them visible and, for a short time, alive.
Each pen depends on the daily fish catch, which makes production unpredictable. Some days the shop can make a small batch, while on other days there are none at all. This limited supply adds to the hype, making each pen feel like a rare item instead of a mass-produced novelty.
However, the worms do not live forever inside the pen, which is important to understand. Reports suggest they survive for only a few days before dying in the liquid. Even so, the idea of carrying something once alive, and potentially still moving, is enough to grab attention instantly.
Why People Can’t Stop Talking About It?
Social media thrives on shock value, and this pen delivers it in seconds. Videos showing the tiny worms floating inside the barrel have spread fast, with reactions ranging from curiosity to pure disgust. Some people treat it as a cool science oddity, while others see it as something straight out of a horror game.
Many online users have compared the pen to items from Resident Evil, a game series known for its creepy biological experiments. That connection has only fueled its popularity, turning the pen into a kind of unofficial fan collectible. People are not just buying it to write, they are buying it to show off.
The humor around the product has also played a big role in its rise. Users have created jokes, fake stories, and dramatic reactions about the parasites escaping. Even those who would never buy it still share it because it feels too bizarre to ignore.
The Controversy Behind the Viral Trend
Trendy's / IG / Critics argue that using living organisms as a novelty item crosses a line, even if the worms are parasites.
The debate centers on whether it is ethical to turn something alive into a product meant for amusement.
There is also a real health concern tied to Anisakis. These parasites can cause a condition called anisakiasis if they are ingested through raw or undercooked fish. Symptoms can include severe stomach pain, nausea, and allergic reactions, which makes the idea of keeping them in a pen feel risky to some people.
The company claims the worms are sealed safely inside the pen’s liquid, which reduces direct risk. Still, concerns remain about what could happen if the pen breaks or leaks. Even a small chance of exposure is enough to make some people uneasy about the product.
The backlash has not been mild either. The shop owner has reportedly received negative messages, including threats, from people who find the concept disturbing. That reaction shows how strongly people feel when something crosses the line between curiosity and discomfort.
This pen sits at a strange intersection of science and novelty. On one hand, it gives a close-up look at organisms most people never see outside a microscope. On the other hand, it turns that experience into something you can carry in your pocket, which feels both fascinating and unsettling.