In the summer of Jia (1223), Genghis Khan went to East India and was stationed in tiemenguan. It is said that the local people sent a monster. This beast has a horn that looks like a deer, but it has a horse's tail, and its whole body is green. Its neighing sounds like human language. Genghis Khan was surprised and asked Lu Yechu. Yeluchucai said: "This beast is called Foot End. It can talk in all directions. It lives well and hates killing. This is a good omen for heaven. The cry just now indicates sweating. You should go back to China early. The emperor is the eldest son of the son of heaven, and everyone in the world is the descendant of the emperor. May Khan inherit God's will and save the people of the world. " Upon hearing this, Genghis Khan immediately decided to end the Western Expedition and move troops back to China.