Karlson On The Roof by Astrid Lindgren
The book revolves around the adventures of a mischievous, self-confident man named Karlson who lives in a small house on the roof of an apartment building. He befriends a young boy named Smidge, who lives in the building below. Together, they embark on various escapades filled with fun and humor, often involving Karlson's quirky inventions and his love for tasty treats. Despite the skepticism of adults, the bond between Karlson and Smidge grows, showcasing a world where the fantastical and the everyday merge through the eyes of a child and his peculiar, flying friend.