'Johan Liebert, otherwise known simply as Johan due to his lack of a formal last name, serves as Monsters main antagonist and one of the primary characters.
Johan, along with his twin sister Anna, was born in 1977 in Prague, Czechoslovakia as part of an experiment to create the perfect children and future leaders of the world. They were the product of a planned relationship between a Czechoslovakian soldier and a political dissident, who planned to flee the nation together, but the father was captured and subsequently executed. Their mother, who went into labor while she was being detained by the Communist authorities, made an escape attempt through the ventilation system and collapsed on the ground near the detention center where she was being held when her water broke. The supervisor of the project, Petr Capek, would claim after their birth that "these are the children who will rule the world."
At some point during their youth, Capek and his superior Franz Bonaparta, arrived at their mother's apartment to collect one of the children to take part in a series of experimental tests. The mother, perhaps confused by Johan's crossdressing to resemble Anna, chose the real Anna instead. After being subjected to the massacre at the Red Rose Mansion, Anna escaped and returned to the apartment, where Johan was waiting for her, still dressed like Anna. Together, they fled the apartment and the city, making their way into the countryside, where they were briefly taken in by a married couple whom Johan later murdered. Escaping once more, they would be continuously adopted by more families, each of whom would be killed by Johan. Eventually, they arrived at the Czech-East German border as a blizzard begin to rage. Nearly freezing and starving to death, the two children were saved by General Wolff of the East German NVA, and were thereafter taken to separate orphanages, supposedly under the protection of Wolff.
While Anna was taken to a better orphanage, Johan was sent to 511 Kinderheim, a government-run orphanage attempting to produce the perfect soldiers, devoid of any emotion.