Immortal Ruyi (如意真仙) is Bull Demon King's brother. He is based in Immortal Gathering Temple (聚仙庵) on Mount Jieyang (解陽山) in Women's Country (女兒國). While in Women's Country, Tang Sanzang and Zhu Bajie unsuspectingly drink from the Spring of Pregnancy and become pregnant. The only cure is to drink from the Spring of Abortion (落胎泉), which is under Ruyi's control. When the women in Women's Country want to drink from the spring, they need to present gifts to Ruyi first. Ruyi holds a grudge against Sun Wukong because of the fate of his nephew, Red Boy, and he behaves in a hostile manner when Sun comes to ask for water from the spring. Ruyi is eventually outwitted and defeated by Sun Wukong.