Traditionally, the Chinese classic novel (often attributed to Wu Cheng’en) follows the pilgrimage of a monk to receive sacred texts from the living Buddha, as he is accompanied by three disciples who swear to protect the monk on the journey as form of atonement for their past sins. The acolytes take on the form of powerful former gods or kings (depending on your interpretation), one of which is the famous Sun Woking, the Monkey King.

Source: Geeks of Doom