Bai Gu Jing (白骨精, lit. "white bone demon") is a yaoguai from Journey to the West, one of the Four Great Classical Novels of Chinese literature.
The four travelers have entered another dangerous region. Sun wu kong leaves to scout around the area, but puts Sanzang and the other two disciploies inside a magic circle. The White-bone Demon (bai gu jing) first uses one of its many transformations to manifest itself as an innocent pretty girl who says she left her father and mother to search for food and that she is willing to share them with Sanzang aka Xuanzang. Sun Wukong who uses his magical eyes could see through her disguise and hits her with the golden banded cudgel and smashes her body but she leaves the body before it is hit a second time. This leads to a fallout with Sanzang and Wukong as Sanzang sees that Wukong's method is too harsh and that it defeats their purpose of finding salvation in all living beings.
As Sanzang eventually forgives Wukong for his action, Bai Gu Jing manifest itself into its next transformation which is the mother of the girl that Wukong first killed. Once again, Wukong sees through the demon's trick, and Wukong beats it one more time with the cudgel to incite Sanzang to further scold him more. With anger, Wukong falls for the demon's trickery once again, Sanzang scolds Wukong but repents for his doing. Sanzang doesn't realize that the demon's intention is to drive Wukong away knowing he is his only protector. Sanzang would once again forgive Wukong but he gives him an ultimatim that he is not to kill anymore.
In the final transformation, Bai Gu Jing manifest itself into the father to seek pity from Sanzang who believes Wukong had killed both his wife and daughter. In the final act, Wukong once again ignores Sanzang's order and kills the last manifestation of the demon, this act led to Sanzang using the Headband tightening spell to punish Wukong. While Wukong refuses to repent for his actions, Sanzang expels him from the journey leaving him to return to Flower Fruit Mountain. Once Wukong is gone, Sanzang and his other disciples soon fall into the demon's trap, as it intends to eat his flesh which is believe to bring immortality. The finale of the story leads to Sanzang's forgivings and the return of Wukong to save the day.
This part of the story brings into debate the argument between Sanzang and Wukong, Wukong acts without thinking and repent as he sees only evil and good, he is the only one that could see through the demon and believes that the only solution is by vanquishing it. On the other hand Sanzang thinks with compassion and believes even if Wukong was right, there are alternatives in dealing with the demon without killing it. The demon also uses the notion of karma to mock Sanzang and his disciples by using karma, its reincarnation from the daughter to the mother and eventually to the father leads Sanzang to feel more pity every time Wukong kills. The eventual outcome of the story allows both Sanzang and Wukong to learn a valuable lesson, as Sanzang must tolerate the means of Wukong in order to be protected while Wukong must learn to understand compassion.