A lively picture-book version of an old Native American story, written by Joseph Bruchac and his son, James, who are of Abenaki heritage. Big bossy Bear brags that he can do anything, including stopping the sun from rising. A skeptical squirrel challenges him on that, and when daybreak comes the next morning, Brown Squirrel gives Bear endless rounds of grief. Bear's anger and a swipe of his paw onto Brown Squirrel's back turn the smaller creature into something else. Young readers won't miss the poor outcomes of bragging and teasing, needless to say. Aruego and Dewey employ a colorful naif style to show all the animals involved as well as the passage of time; Bear is goofy enough not to be really scary. Seven or eight year olds who want to read a shorter book on their own won't go wrong with How Chipmunk Got His Stripes.
I've found that kids love these pourquoi tales. The educators' web site ReadWriteThink gives this helpful definition: "Pourquoi stories are stories or folk tales that explain how or why something exists (usually in nature)." Perhaps part of the appeal for children comes from looking at ordinary things in a new, magical light, too. You can find a long list of additional pourquoi recommendations at the Center for Children's Books.