Why did Xibohou turn into a rabbit when he returned to Xiqiao and spit out his son's meat in the list of gods?

This is a legend, because this little rabbit was spit out by his father, looked around, and then walked straight into Xibohou's palace along the road, wandering in front of Xibohou's wife and mother. The mother-in-law doesn't know where the rabbit came from, but when she saw it, she felt a sense of sadness in her heart. At this time, it was already dark, and the little rabbit went to the yard again and looked up at the sky. Later, Chang 'e took the rabbit to the Moon Palace on the orders of Nu Wa Niangniang, so Boyikao could only become a rabbit instead of a roaring dog. -It's a literary need.