Marvin the Mushroom is for a younger audience of children to promote diversity. As he grows up, he realizes that not all of the mushrooms look exactly like him. Some are taller, some are shorter, some are skinnier, and some wider. They are different colors from each other and grow up in different areas of the forest. With all of these differences though, Marvin knows that they are all mushrooms in the end and they all need to respect each other.