This information was gifted to me by Grace, a dear friend and awesome tour-guide from my too short time in Beijing. Shared with her permission, unedited:

“In Chinese legend, dragon has nine sons:

Bixi, the oldest, is good at carrying heavy burden, and he always carries huge stele on his back, especially stele that inscribed posthumous titles for the emperors, It also expresses filial piety to their forefarthers. Because emperors in China regarded themselves as the sons of dragon.

Fuxi, the second, likes literature, whose image is carved on the top of stele, appreciating beautiful calligraphy.

Qiunu, the third, loves music and is always been decorated on musical instruments.

Yazi, the fourth, valiant and bellicose, his image can be found on the weapons, such as sword, shield and so on.

Qilin, the fifth, he is the symbol of auspiciousness and supreme power. He sits in front of the gate of the imperial palace, or in the imperial garden, with smile on his face. Or be carved on the seats of Buddhas.

Chaofen, the sixth, he is reckless and adventurous, he can be seen on the top of the eaves.

Pulao, the seventh, he is fond of roaring, grasps tightly the big bronze bells.

Bi’an, the eighth, he is just and selfless, can tell right from wrong, so he is carved on the gates of prisons.

Hou, the ninth, squats on the top of marble stele, keeps a eye over the emperor’s behavior, and reminds the emperor of handling state affairs and concerning his people.

You may find many records about dragon and dragon’s sons. In some cases, they have different order and different names. It doesn’t matter, they all vivid, in numerous legends and in every people’s eyes.”