Here’s a woodblock print from Yangliuqing village west of Tianjin, one of nineteenth century China’s most prolific folk-craft centres. It shows the Daoist immortal Zhang Yuanxiao (張遠霄) from Meishan in Sichuan province, driving off the malignant black Heavenly Hound, shown flying away top right on red wings. The hound was believed to cause eclipses by eating the sun, and could …