Because pigs have always brought people a very blessed, fat and festive image, which is in line with the theme.
Pigs are known as Wujin. During the patriarchal clan commune, pigs were a symbol of wealth, and there were 36 pig bones buried in Dahezhuang, Linxia. Tapirs are the sacrifices of the lower class people and the word "home".
People believe that pigs can foretell rain. "Poetry Xiaoya" contains "there are white waves, and the moon is far from the end, making it torrential." In Miscellanies of the Wasted Capital, it is said that Lei Gong "beheaded".