Nils Holgersson is a fictional character from the Swedish novel "The Wonderful Adventures of Nils" written by Selma Lagerlöf. The story follows a young boy named Nils who is transformed into a tiny size and embarks on a journey across Sweden riding on the back of a goose. Throughout his adventures, Nils encounters various animals and learns important lessons about kindness, responsibility, and the beauty of nature. The book is not only a beloved children's story but also serves as a travelogue, showcasing the landscapes and culture of Sweden.