The word 'niu' in Chinese can be translated to cow, bull, or ox, so it is known in English as cow cow, bull bull, and ox ox.
It can be played socially, in the casinos of Cambodia, and online casinos catering to Asian players. There are also variations of it in Malaysia, Vietnam, and probably other places in southeast Asia. Niu Niu is a popular gambling game in south-eastern China and Combodia.