Lillebror is a character from the popular Swedish children's book series written by Astrid Lindgren. He is the younger brother of Karlsson, a mischievous and whimsical character who can fly. Lillebror is often portrayed as kind-hearted and curious, navigating adventures alongside his imaginative friend. The stories featuring Lillebror emphasize themes of friendship, imagination, and childhood wonder. They are set in a charming, everyday world that resonates with young readers, making Lillebror a beloved figure in Swedish literature. The series has been adapted into various media, including films and television shows, further popularizing the character.