The Pout Pout Fish is a really cute book about a fish that thinks he has a "pouty" face because that is how he has also perceived himself. After claiming himself as a pout pout fish for so long, a new friend comes along and shows him a whole different view of himself - a much brighter, happier view.
You could use this story in a kindergarten, first or second grade classroom and have students construct a "pout pout" fish, and have a creative writing sheet that says "I am a pout pout fish when..." that they would complete. You could also do a graphic organizer that has a "kiss kiss" fish and a "pout pout" face, and under each picture would have "I feel cheery/pouty when..."