"The Pigeon Series" is a collection of children's books created by author and illustrator Mo Willems. The series features a lovable, expressive pigeon who often tries to persuade readers to give him what he wants, such as a bus or a cookie. The stories are known for their humor and interactive elements, encouraging children to engage with the text. The first book, "Don't Let the Pigeon Drive the Bus!", was published in 2003 and quickly became popular. The series has received numerous awards and accolades, making it a beloved choice for young readers and their families.