Niu Mo Wang (牛魔王) is a yaoguai with the head of a bull that appears in Journey to the West, a Chinese novel was written and published anonymously by Wu Cheng'en in the 16th century.
In Journey to the West Niu Mo Wang is the Master of the “Mountain of fire” (huoyanshan 火燄山) which burns constantly, causing dryness and unbearable heat in the area and blocking the passage of Tang Sanzang and its troop. Sun Wukong try to steal the magic range bajiaoshan (巴焦扇) of Tieshan gongzhu (鐵扇公主), woman of Niu Mo Wang, only instrument able to extinguish fire. Finally, the demon-bull is overcome with the assistance of Nezha. Niu Mo Wang has a son named Hong haier, (紅孩兒), “red child”.