很久以前，人類的祖先是靠捕捉動物和採集野生果實來維持生活。有一年，發生大水災，地面上的動物都淹死了，果實也爛掉了，很多人因為沒有食物可以吃而餓死。
天上的玉帝趕緊把所有神仙找來一起想辦法，這時，五穀神神農氏提議說：「讓我教導人們種稻米，這樣他們就有米飯吃，不需要冒險去捕捉野獸。」玉帝還決定派馬、牛、羊、雞、狗、豬六種牲畜去幫助人類：馬去拉車，牛來耕田，雞叫人起床工作，狗可以看門，至於羊和豬就提供羊奶和豬肉給人們當食物。
可是，要派誰把稻米送到人間呢？原來從天上到人間，必須經過一片汪洋大海，當時的稻米是從頭到尾都結滿的，加上成熟的稻穗很容易掉落，沒有人願意接下這個辛苦的工作。
這時，灰毛小狗想到人類快要餓死，就說：「讓我來送稻米！」玉帝又說：「路上要小心，因為送到時剩多少稻穀，就表示以後只會結多少稻穀。」接著小狗就把身體弄濕，並在穀堆裏打滾，把金黃的稻穀黏滿全身後就跳進大海，小狗用力把尾巴高高豎起來，跳過一個個巨浪，終於到了地面，但是小狗身上的稻穀都被沖走了，只剩下高高抬起的尾巴頂端還有一點點。從此以後，地面上的稻米只有頂端結稻穀。
Once upon a time, the forefathers of human beings hunted animals and foraged wild berries for sustenance. One year, there was a great flood that drowned all the animals and ruined all the wild berries. Many people died of starvation.
Seeing this, the Jade Emperor gathered all the gods in heaven to think of a way to save mankind. Sheng Nong, the God of Grains, put forth a suggestion, “Let me teach mankind how to grow rice so that they will have rice to eat and do not have to hunt for dangerous wild animals.” The Jade Emperor also decided to send six animals to help mankind: the horse, buffalo, sheep, chicken, dog and pig. The horse pulls the carts. The buffalo ploughs the fields. The chicken wakes people up to go to work. The dog guards the house. The sheep provides milk, and the pig is raised to provide meat as food for mankind.
But, who should be tasked with taking the magical stalk of rice to the mortal realm? The rice had to be carried across a great ocean that separated Heaven and Earth. The original stalk of rice was covered with grains along its entire length. Furthermore, the ripened grains fell off easily. Therefore, no one was willing to volunteer for this difficult task.
But the little gray-haired dog thought of the starving humans and said, “Let me do it!” The Jade Emperor told the dog, “Take care of the rice along the way, for the number of grains of rice remaining on you when you arrive in the mortal realm will determine the amount of rice that will grow per stalk henceforth.”The dog wet his fur and rolled about in the grains to cover himself with them. Then, he jumped into the sea and swam with his tail above water to keep the grains from being washed away. He jumped over one wave after another before finally arriving in the mortal realm. However, most of the grains had been washed away by the ocean. The few grains that were left, were at the tip of the dog’s tail. Since then, only the tip of the rice stalk has produced rice grains.
