Known as the Great Sage Equalling Heaven (斉天大聖, Seiten Taisei?), Sun Wukong was the disciple of Xuanzang, following her across India with his fellow disciples. During his adventures, he was punished by Shakyamuni, reaching the "edge of the world" only to find that it was Shakyamuni's palm.
Sun Wukong briefly appears when thought of by Kohaku as an original Servant in the lead-up to the reveal of Sakura Saber, but is quickly discarded after two pages as part of a gag. Although discarded, he appears on the cover of a volume, so it is unknown if he will remain a recurring character.
Sun Wukong is said to be the equal of Nezha. In the Koha-Ace scenario, he is depicted as a Servant briefly as part of a gag. He shows the ability to swap between a male and female form at will. His Noble Phantasms are the Ruyi Jingu Bang (天河鎮定神珍鉄(通称・如意金箍棒), As You Will it Staff or Cudgel?), golden chain mail shirt (鎖子黄金甲, ?), phoenix-feather cap (鳳翅紫金冠, ?), and cloud-walking boots (藕糸歩雲履, ?). He can use a Reality Marble-like skill that involves a process similar to Tsubame Gaeshi on a much larger scale.