The illustrations for this book were done in watercolor and pen and ink on illustration board.
This book would be hard to use in a group much bigger than 10, but it would terrific for a small group or one-on-one with a child.
This is the kind of book that begs to be looked at together, with a child on your lap and quietly looking through the pages, then going back through it and talking about each page, and discussing what is going on and what might happen. In Early Literacy circles you could easily use talking, reading, and writing practices. Since there are no words in the major story portion, a child can 'read' the story, an adult could write what the child dictates, then the child could illustrate their own story. Having a conversation around a book leads to longer attention span, larger vocabulary, and that wonderful feeling of sharing something amazing with a loved one. All of these create the 'print motivation' skill or you may recognize it as one more piece of the connection to getting ready to learn to read.
I did not have much luck finding a non-commercial Holly Hobbie website. There is an author's note at the end of the book of toad facts, but no bibliography was given.