Piggly the Angry Piglet: A cute and educational story about anger for kids ages 1-3,4-6

It is true that the only thing that we can really change is our attitude. Piggly, who lives on a farm of happy, singing pigs, has a bad attitude. He is angry all the time, and when his friends are singing and dancing and having a great time, he is sulking and calling them names. He is miserable while they are happy. Can anything happen that will cause Piggly to change his attitude, or will he be a sad and miserable pig for all his life?