Suzaku, Xuanwu, Qinglong and Baihu are four kinds of mythical animals in ancient China, representing 28 places in four directions. Xuanwu is also called "Zhenwu Emperor", but Xuanwu actually refers to the tortoise. The tortoise has a long life, so it is still a symbol of immortality. In the dream, the tortoise turned into a man, and the Zhenwu Emperor appeared. The tortoise didn't catch it, but followed you and your mother home. This shows that Emperor Zhenwu wants to tell your family good luck and will follow you home without being caught by you, so this is actually a symbol of good luck. Maybe the answer is a little superstitious, just to help you interpret your dreams.