I am divided on this book. In some ways it is cute, in others it does seem like it could be a bit.... problematic. I don't know exactly why, it just doesn't seem like a great thing to tell kids.
This would be a good to start with when first introducing transitional books. There are a few words using in the book which would be helpful to know what words the students know. It is also a good for a read aloud because it is a predictable book and the students could join in the reading.