 He appeared on a 1980 episode of children's television show "Mister Rogers' Neighborhood".Most of O'Callahan's early stories were developed from improvised bedtime tales for his two children, and are highly whimsical and showcase O'Callahan's talent for vocal characterization (including giving personalities to inanimate objects), rhythmic verbal poetry, his gentle absurdist humor, and ability to enter into a child's perception of the world.Notable stories of this type include "The Little Dragon", "Tulips", "The Bubble", "The Red Ball", and "Orange Cheeks".