A symbol, of course, is something that stands for something else. In literature, and especially in novels, symbols become a very important bit of figurative language. This book is no exception.
In this educator's opinion, the most prominent symbol in the book is Mother Paula's All-American Pancake House. Further, there is a definite conflict between greed and environmental protection. That is what this book is most truly about. The pancake house is always a symbol for corporate greed and its negative effects in the community. The pancake house is being built right on top of people's homes. Trying to stop the building of the pancake house is what knits all of the characters in the book together. They are all working together against the idea of corporate greed. Therefore, this is probably the most prominent symbol in the book.
Of course, this book becomes quite an environmental novel. Most of the characters are both animals and people trying to protect their homes from the corporate greed that is represented by Mother Paula's All-American Pancake House.