Why is it called Liu Jinu? It is said that it was the nickname of Emperor Wu of Song Wudi in the Southern Dynasties. Before he became emperor, he led troops to win the battle. When chasing down enemy remnants, he met a big snake in the way. He shot an arrow at the snake and went there the next day to see it. He heard someone smashing something, and found several children working on it. When he asked, he realized that their king was wounded by an arrow.