Ox-Head (simplified Chinese: 牛头; traditional Chinese: 牛頭; pinyin: niú tóu) and Horse-Face (simplified Chinese: 马面; traditional Chinese: 馬面; pinyin: mǎ miàn) are two fearsome guardians or types guardian of the Underworld in Chinese mythology, where the dead face suffering prior to reincarnation. As indicated by their names, Ox-head has the head of an ox, and Horse-face has the face of a horse. They are the first people a dead soul meets upon arriving in the Underworld; in many stories they directly escort the newly dead to the Underworld. Usually, the two are mentioned together (牛头马面/牛頭馬面). Occasionally however, some souls manage to escape their clutches to roam on earth under the guise of a human facade, but Yim Los far-seeing eyes means Ox-Head and Horse-Face are typically dispatched in time to capture these lost souls.
In the Chinese classic novel Journey to the West, at one point Horse-Faces and Ox-Heads are sent to capture Sun Wukong, the Monkey King. Sun Wukong overpowers them and scares them away. He then breaks into the Underworld and crosses out the names of himself and his people from the record of living souls, hence granting immortality to himself and his monkey followers. In Japanese mythology the two are known as "Gozu (牛頭)" and "Mezu (馬頭)".