漢族民間故事說:當年軒轅黃帝要選十二動物擔任宮廷衛士,貓托老鼠報名,老鼠給忘了,結果貓沒有選上,從此與鼠結下冤家。大象也來參賽,被老鼠鑽進鼻子,給趕跑了,其餘的動物,原本推牛為首,老鼠卻竄到牛背上,豬也跟著起哄 ,於是老鼠排第一,豬排最後。虎和龍不服,被封為山中之王和海中之王,排在鼠和牛的後面。兔子又不服,和龍賽跑,結果排在了龍的前面。狗又不平,一氣之下咬了兔子,為此被罰在了倒數第二。蛇、馬、羊、猴、雞也經過一番較量,一一排定了位置,最後形成了鼠、牛、虎、兔、龍、蛇、馬、羊、猴、雞、狗、豬的順序。
The Chinese animal signs are a 12-year cycle used for dating the years. Every year is assigned an animal name or "sign" according to a repeating cycle: Rat, Ox, Tiger, Rabbit, Dragon, Snake, Horse, Sheep, Monkey, Rooster, Dog, and Boar. Therefore, every twelve years the same animal name or "sign" would reappear.