Elder Zhang Guo or
Zhang Guo Lao,
Chang Kuo Lao in
Wade-Giles, (張果老 in
pinyin: zhang1 guo3 lao3) is one of the
Eight Immortals. He is known as Master Comprehension-of-Profundity (通玄先生 tong1 zhao4 xian1 shen1). He lived as a
occultist-
alchemist (方士) on Mount Tiao (條山) in Heng Prefecture (恒州 heng2 zhou1) during
Tang Dynasty. By the time of
Empress Wu, he claimed to be several-hundred-year-old. Empress Wu summoned him to leave the mountain, so he feigned death. He is the personification of a
white bat. He rides a white
donkey backward. Tang Tang Emperor Xuan Zong (唐玄宗) attempted to give him an office with the title of Silvery Blue Guanglu Minister (銀青光祿大夫) ("guanglu minister" is a rank).