No matter what parents do, sometimes Mr. Crabby Pants takes over their child's personality. So what is a parent to do? They try to find the fastest way to get Mr. Crabby Pants to leave. After picking up her son from daycare one day, J.L. Peck came up with the idea for Mr. Crabby Pants after she realized her son was crabby. To keep the drive home interesting and fun, she encouraged her son to help make up the story with her. Her son had lots of fun helping to decide the outfit and activities for Mr. Crabby Pants.