Answer:
Elsa Korr is a Jewish girl who is hidden by Rosie Betzler, Jojo's mother, in their attic in Nazi Germany during World War II. Her character serves as a representation of the victims of the Nazi regime and the horrors they faced. Elsa's presence challenges Jojo's beliefs, as he gradually realizes the true nature of the Nazi propaganda and the humanity of those who were demonized. She plays a critical role in shaping Jojo's transformation from a fanatic Nazi youth to a more empathetic and tolerant individual.