Cao Guojiu was the newest of the Eight Immortals. He is shown in the official's court dress with a jade tablet. Sometimes he holds castanets.His jade tablet can purify the environment.

Cao Guojiu was said to be the uncle of the Emperor of the Song Empire, being the younger brother of Empress Dowager Cao. In historic records, there were several Emperor-consorts Caos in the Song Empire, but only one became empress: Cishengguangxian Empress(1015 - 1079), the wife of the fourth Song emperor, Renzong, none of whose children became an emperor.

Cao Guojiu's younger brother Cao Jingzhi was a bully, but no one dared to prosecute him because of his powerful connections, not even after he killed a person. Royal Uncle Cao was so overwhelmed by sadness and shame on his brother that he resigned his office and left home.