Marshal Heavenly Mugwort is a Taoist protective deity. Wikidata and the cited Chinese Wikipedia both record this title and do not give a separate personal name, so the title stays unchanged.[1][2]
Role
The Chinese Wikipedia counts him among the Four Sages of the North and describes him as their leader, a commander of divine troops who drives off evil, and one of the heads of the thunder ministry. It also treats him as one lodge of the Northern Dipper, later honored as a star god and pictured as a general under the Purple Tenuity Emperor: three heads, six arms, and a broad-axe, set over the Dipper and Fengdu. The same page gives the further titles Tianpeng zhenjun and Grand Marshal Tianpeng, and records him as male.[2]
The novel character
That article says the title used for Zhu Bajie in the Ming-Qing novel Journey to the West is not the same figure as this marshal of the Four Sages.[2] This site also has a page for Journey to the West.