"A snake swallowing an elephant" (蛇吞象 shé tūn xiàng).

This three-character idiom comes from the Classic of Mountains and Seas (山海经), an ancient Chinese text of mythical geography compiled around the 4th century BCE, with contributions attributed to the mythical emperor Yu the Great (大禹).

The original passage reads:

"The Ba serpent devoured an elephant, and only after three years did it spit out the bones."

巴蛇食象，三岁而出其骨

The Ba Serpent (巴蛇) was a mythological creature inhabiting southwest China's waters, so enormous it could swallow elephants whole and digest them over years.

By the Ming Dynasty, this image evolved into a proverb about human nature, popularized by scholar Luo Hongxian (羅洪先) in his Awakening Song (《醒世歌》):

"The human heart is never satisfied, like a snake trying to swallow an elephant."

"人心不足蛇吞象" (rén xīn bù zú shé tūn xiàng)

In modern business Chinese, "a snake swallowing an elephant" describes when a smaller company attempts to acquire a much larger one—biting off more than it can chew.

Example:

Anta's 2019 acquisition of Amer Sports was called a "snake swallowing an elephant" deal.

安踏2019年收购亚玛芬被称为蛇吞象交易。