Chinese idiom · 成语
为虎作伥
Meaning
To aid a tiger as its ghost; to assist evil.
Character by character
Origin and story
legendTang collections of supernatural tales describe chang ghosts: people eaten by tigers whose spirits are then made to serve those animals. In the account of Ma Zheng from Pei Xing’s Chuanqi (傳奇), preserved in Taiping Guangji, two travelers escape a tiger disguised as a monk. Later, sheltering with a hunter, they see a crowd of spirits release the hunter’s trap before another tiger arrives. The hunter explains that these are tiger victims clearing a safe path for their master. He resets the weapon, and it kills the tiger.
The legend supplies the unsettling image of victims serving a predator. In ordinary language the idiom condemns helping a wrongdoer harm others; the ghosts belong to folklore, not historical evidence.
Sources and further reading
In everyday life
明知是假货还帮忙写好评，就是为虎作伥。
Knowingly writing positive reviews for counterfeit goods is helping the wrongdoers.
Strongly disapproving: deliberate assistance to someone doing harm, not ordinary teamwork.