Did you know Monkey’s surname is a pun for immortality? I’ve previously mentioned that his surname Sun (孫, “macaque” or “grandson”) was chosen because he resembles a macaque monkey (猢猻, husun), and his given name Wukong (悟空, “awakened to emptiness”) is most likely based on the religious moniker of an 8th-century Chinese Buddhist monk who lived in India. However, the surname references Daoist internal practices. Talking about the individual components of the surname, the patriarch Subhuti states: “Zi [子] means boy and xi [系] means baby, and that name exactly accords with the fundamental Doctrine of the Baby Boy [正合嬰兒之本論]. So your surname will be Sun” (Wu & Yu, 2012, p. 115). Comparative religious scholar and JTTW translator Anthony C. Yu explains, “The Baby Boy is none other than the ‘holy embryo or shengtai 聖胎,’ the avatar of the realized state of immortality in the adept’s body” (Wu & Yu, 2012, p. 86). Daoist doctrine dictates that the three vital essences of jing (semen), qi (breath), and shen (spirit) combine to create this holy embryo. Daoist and Buddhist texts sometimes illustrate realized immortality or enlightenment as the image of a baby on a practitioner’s stomach.

Source:

Wu, C., & Yu, A. C. (2012). The journey to the West: Volume 1. Chicago, Illinois : University of Chicago Press.