Mungwortt was the son of the lecherous male gorilla Digby and the female chimp Nila. He bore a strong resemblance to his half-brothers Marcus and Simka. As a half-breed and an alcoholic he was an outcast, reduced to the role of a garbage-ape of Ape City, and as such, wore the dark purple woven garments of the civil service. Despite his status and her social aspirations, he was conducting a secret affair with Liet, the wife of Dr. Galen. He witnessed the human Landon speaking with Dr. Milo at Galen's laboratory. When he was caught in Liet's bedroom by Galen he was arrested as an intruder, and though Liet tried to persuade Galen to drop the charges she seemed less attached to Mungwortt than he was to her. He revealed his story about Landon to the authorities, hoping to bargain for his freedom, but instead he was considered a danger to the peace.
Held in custody for days by Marcus, who suspected the truth about Mungwortt and Liet, both Mungwortt and Zao were secretly transported to the Forbidden Zone by Marcus' successor Cerek, acting on the instructions of Dr. Zaius. There, they were thrown into a pit at night and soon found themselves surrounded by the 'White Ones' - seemingly some sort of mutated or hybrid ape/human race of carnivores who had hairless ape-shaped bodies and white hair and fur on their flat-nosed faces and heads. This was the standard practice for the most dangerous ape dissidents, thus avoiding the sacred law "Ape Shall Not Kill Ape".
After a struggle with the White Ones, Zao died and was eaten by them. Mungwortt, however, survived and took Zao's skull with him as an imaginary companion on his journey through the mutant city. He encountered the White Ones' controllers - giant living brains known as the ‘Inheritors’. They had become subjugated by the mutants of the Fellowship and now worked on their behalf. Against the odds, Mungwortt found a way to ally with the White Ones and take revenge on their tormentors. In an attempt to blend in with the invading gorilla army, Mungwortt then dons a stolen uniform and is the ape who fires his machine gun into the apparently empty jail cell where Taylor, Nova and Brent are hiding.
Mungworth managed to make his way to the Mutant Cathedral, where he witnessed Taylor detonate the Alpha-Omega Bomb which killed him and destroyed the entire planet.
- Mungwortt is exclusive to the 2011 novel Conspiracy of the Planet of the Apes and its 2018 sequel Death of the Planet of the Apes.
- The character was based on Mungwort, a hybrid soldier in the mythos of the Return to the Planet of the Apes animated series.