Back of book description:
This is the story of Anna, a third-grade student who has an unusual companion—a monkey in her backpack! Not everyone can see him, but he causes a lot of trouble for Anna by mixing up her spelling letters, distracting her in class, and making it hard for her to keep up with the other kids. He causes so many problems for her that Anna wonders if she will ever make it to the end of third grade with the other children. But she learns that her troublesome monkey companion can also be a big help to her if she lets herself understand, accept, and appreciate her unique situation.