SHANGHAI, Jan. 31 -- It started with a simple production error - a mouth stitched the wrong way round - and ended with a factory worker in Yiwu, China, being promised 12 years' worth of ang pow.

The now-famous "cry-cry horse" plushie had been designed as a cheerful mascot for the coming Year of the Horse.

But on the assembly line in Zhejiang province, a worker named Bao accidentally sewed its smile upside down, giving the toy a deeply unimpressed pout.

Factory owner Zhang Huoqing later explained, "It was simply a worker's mistake - the mouth was sewn upside down."

The flawed toy might have gone unnoticed if not for a woman in Hangzhou who requested a replacement and posted photos of its miserable expression online.

Within hours, Chin...