A protective and rule-setting figure in Billy's life who restricts him from exploring the Forest of Sin due to its perceived dangers. She often checks on Billy from a distance while busy with her housework.

The leader of the tiny, tree-dwelling Minpins, who forms a friendship with Billy. He provides crucial information that helps Billy understand the Minpins' world and their challenges.

A fearsome monster residing in the Forest of Sin, known for terrorizing the Minpins. This creature is drawn to larger meals and becomes a significant adversary in the story.

The biggest bird in the Forest of Sin, who forms a non-verbal yet trusting partnership with Billy. Swan plays a key role in Billy's adventures and in helping to navigate the forest.

A mysterious figure whose whispering serves as the catalyst for Billy's adventure into the forbidden forest. This character represents Billy's internal urge to explore and make independent decisions.