Bo Yi 伯益, also written 伯夷, 伯翳 or 柏翳 and also called Yi 益 or Da Fei 大費, is a mythological person of ancient China. He is said to have been born out of an egg laid by a swallow (yan 燕) as a representative of the realm of birds. He was therefore able to communicate with all animals, as the biography of Cai Yong 蔡邕 in the official dynastic history Houhanshu 後漢書 says.
The history book Shiji 史記 narrates the story of his birth. A descendant of Emperor Zhuan Xu 顓頊, Nü Xiu 女脩, swallowed an egg produced by a black bird, and gave birth to Da Ye 大業. Da Ye married Nü Hua 女華, daughter of Emperor Shao Dian 少典, and fathered Da Fei, who assisted Yu the Great 大禹 in taming the floods, together with Hou Ji 后稷 and Gao Yao 皋陶. The emperor rewarded Da Fei with black streamer (zaoyou 皁游). Da Fei married a daughter from the chieftain of the Yao 姚 tribe and continued assisting Emperor Shun 舜 in the taming of wild animals. Da Fei was then given the name of Bo Yi 柏翳 and bestowed the surname of Ying 嬴, so that he is seen as the ancestor of families with that surname, especially the house of Qin 秦.
Bo Yi also instructed mankind in hunting and cattle breeding, showed them how to construct traps and how to raise husbandry animals. He also invented the digging of wells, as the book Lüshi chunqiu 呂氏春秋 says, and by this activity repelled dragons and mystic animals from all waters. According to the book Mengzi 孟子, Emperor Shun sent him to all region of the empire to teach the population the use of fire.
Bo Yi's epiteths were "leader of animals" or "general of the worms". The Qing period 清 (1644-1911) scholar Liang Yusheng 梁玉繩 (early 19th cent.) gives a very interesting explanation for a sentence in the Classic Shangshu 尚書: Yi, actually Yan 燕, the king of birds (phoenix), offered cessation to four other ministers, representing wild animals like tiger, panther and bear. Yu the Great also entrusted him with important government tasks and later even pland to hand the throne over to him as the most worthy of men, as a story in the ancient history Zhushu jinian 竹書紀年 goes, but Yu's son Qi 啓 usurped the throne and so founded the Xia dynasty 夏 (17th-15th cent. BCE). This story is also told in the Zhanguoce 戰國策 and the elegy Tianwen 天問 in the collection Chuci 楚辭 "Poetry of the South".
The Yuejueshu 越絕書 continued the story and report that later on Qi, repenting the early death of Bo Yi, brought annual offerings to him in a shrine. According to the Shangshu and the Shiben 世本 genealogies, Qi was the first to promulgate a penal law canon or invented the five capital punishments (wuxing 五刑). These were introduced after the Yellow Emperor 黃帝 had defeated the rebel Chi You 蚩尤.
In the book Shuoyuan 說苑, Bo Yi is said to have been chamberlain for ceremonials (zhizong 秩宗), and so the mythical person merges with an historical person of the late Shang period who was the ancestor of Qi Taigong 齊太公, founder of the house of Qi 齊.