Bai Yingteng was originally a little white snake that was cultivated in the mountains of Yongzhou. One day, a snake hunter captured it and offered it to the emperor for soaking in medicinal wine. When he was about to be killed, the young imperial doctor Xu Xian felt pity and rescued the little white snake, and released the little white snake. Bai Yingteng vowed that this life-saving grace would be remembered forever. After more than 1,200 years of practice, Bai Yingteng finally shed her snake body and transformed into a human form. He originally wanted to go to Mount Emei to continue cultivating immortality, but after the guidance of Master Guanyin, he recalled that there was still a period of unpaid kindness in the world. Following the instructions, he came to the Su River in Donghai City to find the descendants of Xu Xian, his savior in his previous life.