Nang Phengsi was the girl of a hermit, Chao Laksi, who had quit his monotonous retreat and by magical powers had changed his own excrement into a beautiful maiden named Nang Khaysi (body dirt), then made her his wife.   In due time, she gave birth to a daughter.  The father named her Nang Phengsi.   When Chao Laksi was gone out to fetch fruit in the forest, Phra Athit, the God of the Sun, came into his cavern and commited adultery with Nang Khaysi.  In course of time, she gave birth to two twin sons named Thao Sang Khip and Thao Phalichanh.