Reported by BBC Business
Ensito, with his custom-made Labubu teeth, posing with a new doll in his collection
Collectors young and old energetically snapped up "blind boxes" - sealed, mystery packages containing the quirky monsters - often paying $15 (£11) or more.
Those unable to get the characters they wanted were often prepared to pay much more on the resale market.
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The hype around the creatures convinced a mega-fan from North Carolina, who goes by the name Ensito, to leave his tech job in 2024 to create Labubu content full-time, travelling as far as Italy and Spain to seek out the latest releases.
Ensito has spent more than $50,000 (£37,000) to build his collection of more than 400 Labubus, a figure he tells the BBC he's "embarrassed to say".
He even had a row of custom Labubu-like jagged teeth made by a dentist to wear at events.
But in recent months, Ensito's once-viral posts about the furry monsters have struggled. "Those videos used to be able to hit 10,000 really quickly but I'm struggling to do that now."
Ensito's focus has shifted to other trends like Hello Kitty and squishies.
It's a sign that the craze which made parent company Pop Mart worth more than US toy giants Hasbro and Mattel put together may be running out of steam. Analysts believe the Beijing-based brand is struggling to capture excitement beyond a single viral moment.
Pop Mart recently reported that global sales in the three months to the end of September had fallen by as much as 50% on the previous year.
The drop was particularly steep outside mainland China, with US revenue down by at least 70%.
Pop Mart didn't invent blind boxes but its dolls certainly helped to popularise them around the world.
The sales tactic made collecting feel "nostalgic", evoking the feeling of opening gifts as a child, says marketing professional Katelynn Carlson, who discovered Labubus through social media and now owns 36 of them.
One of her first Labubus was a rare doll, making the experience "even more exciting", she adds.
Labubu, which launched in 2019, has been Pop Mart's most…