🐱 Somewhere in Henan, a mouse became the best unpaid marketer Weilong ever had. Within days the brand had turned the joke into an actual product on shelves. This is one worth studying closely, because most brands see a strange viral moment and just post a meme about it. Weilong turned it into a business decision.
The air conditioner nobody expected to be a snack warehouse
The story starts at a car dealership in Xuchang, Henan. The staff room air conditioner had been sitting unused for a while, and when it finally broke down, a repair technician opened the casing to fix it. Instead of dust and loose wiring, he found the whole unit packed with Weilong biscuit wrappers, all of them still sealed. A mouse had been stockpiling snacks inside the machine for what looks like a long stretch of time, and nobody noticed until the air conditioner stopped working and someone had to look inside.
Photos of the discovery spread fast on Chinese social media. It is the kind of story that writes its own headline: a rodent with better brand loyalty than most snack buyers, quietly building a private stash of one single product. According to SocialBeta’s weekly marketing case roundup (“本周值得关注的 6 个品牌营销案例 | 案例一周 Vol.405”), the story spread widely enough, and fast enough, that Weilong could not stay quiet, and clearly did not want to.
How Weilong answered, and it was fast
The brand’s social team moved inside the same news cycle the story broke in, which is the part most companies get wrong. First came the tone-setting joke, a public thank you to the mouse for confirming that the biscuits taste good. Then a mock safety notice, warning customers, and rodents, that hoarding snacks inside electrical appliances is a fire risk. Then the piece that made the story travel even further: a fake official document titled the “Reply Letter From the General Administration of Mouse Hoarding,” written in the flat, deadpan tone of a government notice. Weilong followed that with an open call for its followers to submit their own translations of “mouse language,” which turned a one day news item into a running joke people kept adding to on their own.
None of this needed a production budget. It needed someone with the authority to post within hours, a tone that already matched the brand’s playful reputation, and a legal read that took minutes rather than weeks. Weilong has spent years building an internet voice that is a little cheeky and never too corporate, and that groundwork is exactly what let the team react without sounding like they were trying too hard.
From joke to product line
The part that makes this case worth more than a laugh is what happened next. Weilong did not stop at content. It launched a new product line built around a cat mascot, cookies packaged with cat graphics and named 「鼠鼠不敢偷的饼干」, which translates to “Cookies the Mice Wouldn’t Dare Steal.” The name and the mascot both point straight back to the original story, so anyone who saw the viral post recognizes the joke the moment they see the pack on the shelf. Weilong turned a passive news item into an active reason to walk down the snack aisle and pick something new.
This is the move most brands skip. A meme earns a like and a share. A product earns a purchase. Weilong let the internet write the concept and the name for a new item, for free, in public, in front of an audience that was already primed to buy it because they had already laughed at the story once. The cat mascot also adds a second layer of humor for anyone who knows the punchline, cats are supposed to catch mice, not sell them snacks.
What Philip Chen makes of it
I get asked a version of this question every few weeks by clients: should we jump on this trend that is going around Chinese social media right now? Most of the time my answer is no, and the Weilong case is a good way to explain why this one was different.
The first filter is simple. Does the viral moment already involve your product in a positive light, without you paying for it or staging it? A mouse choosing to hoard your snack, intact, over months, is free proof that people want what you sell. That is a completely different category from a meme that is funny but has nothing to do with what you make. Brands waste money chasing the second kind and calling it “newsjacking.” Only the first kind is worth turning into a product.
The second filter is whether the moment has legs past 48 hours. A joke that peaks on day one and fades by day three is content, not a product brief. Weilong could tell the story had staying power because people kept generating their own jokes around it, the mouse translations, the fake government letter format, the safety warning memes. When an audience keeps building on a story without being asked, that is your signal the concept can support a real product, not just a post.
For a foreign brand, the realistic process looks like this. Set up light social listening on the platforms where your category actually lives, and read our guide on building a real Douyin strategy if you have not started yet. Give one person, not a committee, the authority to post a reaction within the first day, in the brand’s normal voice. Then wait a few more days before committing production money to a physical product, so you react to a real trend and not a Tuesday afternoon spike. The same reaction-speed muscle applies any time a cultural moment breaks in China, and our team lays out how to be ready for one in how China’s cultural moments drive sales, so the reflexes are already in place the next time a moment like this one hits.
Last point, and it matters most for brands based outside China. Do not force it. If your Chinese team has to explain the joke to headquarters for approval, you have already lost the speed that made Weilong’s response work. Give local teams a short list of what they can post without sign off, and trust them to know when a mouse in an air conditioner is actually worth a reply.
Source (Chinese): SocialBeta, “本周值得关注的 6 个品牌营销案例 | 案例一周 Vol.405,” socialbeta.com/article/111219. The case describes how a mouse’s hidden stash of Weilong biscuits, found inside a broken air conditioner at a Henan car dealership, went viral and led Weilong to launch a cat themed cookie line named “Cookies the Mice Wouldn’t Dare Steal.”
See also our roundup of the top 50 China ad campaigns of H1 2026 for more examples of Chinese brands turning attention into sales.
About the author. Philip Chen is CEO of GMA (Gentlemen Marketing Agency), a digital marketing agency focused on the Chinese market. GMA has helped more than 1,000 brands grow in China across Baidu, WeChat, Douyin, Xiaohongshu and cross border e-commerce. Connect with Philip on LinkedIn.
