The Monkey is paired with shen, the ninth earthly branch, whose double-hour runs from three to five in the afternoon and whose phase is metal. The traits given to the sign, cleverness, versatility, curiosity, humour and a certain disregard for rules, are strongly coloured by the most famous monkey in Chinese literature: Sun Wukong, the Monkey King of the sixteenth-century novel Journey to the West, who steals the peaches of immortality, wrecks the celestial banquet, is subdued by the Buddha and finally escorts the monk Xuanzang to India in search of scriptures. He is a trickster who becomes a pilgrim, and the mixture of irreverence and eventual devotion is very much the character the sign is credited with. Monkey figures also appear widely in Chinese folk religion, and the novel itself is a Buddhist and Daoist allegory as much as an adventure.
Sun Wukong's popularity has carried the sign's cultural weight far beyond China itself: the Monkey King is a major figure in Japanese, Korean and Southeast Asian popular culture through translated and adapted versions of Journey to the West, and the character has been continuously reinterpreted in Chinese opera, television and film since the sixteenth-century novel's composition, making Monkey arguably the single most internationally recognisable figure among all twelve animals of the cycle, ahead even of the dragon in name recognition outside East Asia specifically because of the character's individual literary fame.