|Water Margin character|
|Nickname||"Knife Wielding Demon"
|Rank||81st, Ji Star (地嵇星) of the 72 Earthly Fiends|
|Chief butcher of Liangshan|
|First appearance||Chapter 17|
Cao Zheng is a fictional character in the Water Margin, one of the Four Great Classical Novels of Chinese literature. He ranks 81st of the 108 Liangshan heroes and 45th of the 72 Earthly Fiends. He is nicknamed "Knife Wielding Demon".
Cao Zheng is from a family of butchers in Kaifeng, Henan. He has a reputation for being an excellent butcher and had learnt martial arts from Lin Chong before. He travels to Shandong to run a business but fails and ends up heavily in debt. He owes his landlord a large sum of money and cannot afford the expenses for his journey home. He runs a rented restaurant near Yellow Soil Ridge to earn some money to pay his debt.
Becoming an outlaw
Yang Zhi is appointed to lead a group of men to escort a convoy of birthday gifts for the Imperial Tutor Cai Jing. They are tricked and knocked out by Chao Gai and his six friends at Yellow Soil Ridge, who rob them of the gifts. Yang Zhi deserts his men after the failed mission and wanders around in despair. He reaches Cao Zheng's restaurant and attempts to leave after having a meal without paying. Cao Zheng stops him and they fight. Although Cao Zheng uses a pole as a weapon against the bare-handed Yang Zhi, he still loses to his opponent. They are impressed with each other's skill and become friends after self-introduction.
Cao Zheng suggests to Yang Zhi to join the bandit gang on the nearby Mount Twin Dragons. They travel there and meet Lu Zhishen along the way. Lu Zhishen tells them that Deng Long, the bandit leader, refused to let him join the gang and denied him entry to the stronghold. Cao Zheng devises a plan for the three of them to seize control of Deng Long's stronghold.
Lu Zhishen pretends to be drunk and allows Cao Zheng and Yang Zhi to tie him up and send him to Deng Long. Deng Long is pleased when he sees Lu Zhishen and wants to kill Lu. Just then, Lu Zhishen awakes and breaks free. The trio kill Deng Long and seize control over the stronghold, replacing Deng as the leaders of the gang. Cao Zheng follows the outlaws to Liangshan Marsh for the Grand Assembly in chapter 71.
Campaigns and death
Cao Zheng becomes the chief butcher of Liangshan after the Grand Assembly. He is in charge of overseeing the slaughtering of cattle and poultry. He follows the Liangshan heroes on their campaigns against the Liao invaders and rebel forces after they have been granted amnesty by the emperor. He is killed by a poisoned arrow in the battle of Xuanzhou during the Fang La campaign.
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- Buck, Pearl. All Men are Brothers. Moyer Bell Ltd, 2006. ISBN 9781559213035.
- Zhang, Lin Ching. Biographies of Characters in Water Margin. Writers Publishing House, 2009. ISBN 978-7506344784.
- Keffer, David. Outlaws of the Marsh.
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