Wearing his favorite hat, Mattison Mouse is happy to venture outside on a beautiful day. Soon the little mouse hears mysterious footsteps behind him. What started out as a cheerful stroll turns uncertain as he begins to count animals who appear to be shadowing him. In a rush to run away, Mattison trips and loses his hat. It's only then he learns to refocus and overcome his anxieties, surprised by the special party his animal friends have planned for him.

Children can help count the fun party favors as everyone joyfully celebrates Mattison's best birthday ever.