In the anime *Jack and the Witch*, Barnaby Bear, known as "Little Bear," is Jack's loyal bear cub companion. He lives with Jack and other animal friends—Dinah Dog, Phineas Fox, and Squeaker Mouse—in a forest house. Barnaby possesses a generally laid-back and friendly nature but demonstrates decisiveness when required.

He shows loyalty and bravery opposing the witch Auriana and her forces. After Auriana's machine transforms Squeaker Mouse into a harpy, Barnaby plays a critical role in resisting the witch. His unexpected laughter during a tense encounter with the harpy Harvey diffuses hostility, creating a temporary truce. Later, he deduces the giant windmill powers Auriana's transformation machine. He immobilizes the windmill to prevent Jack from being sucked in, but this causes other harpies to be pulled into the device instead, overloading and destroying it.

Following the explosion, Auriana captures Barnaby and the other animals, imprisoning them in magic bottles. He escapes after Squeaker Mouse cracks the queen's crystal ball, breaking the spell. Recognizing the crystal ball as the source of Auriana's power, Barnaby throws it out a window, shattering it. This strips Auriana of her magic, transforming her into a goblin-like creature. Barnaby then participates in the pursuit of the fleeing Auriana, culminating in her defeat.

His actions directly contribute to the destruction of Auriana's castle and the reversal of her spells, restoring all transformed harpies, including Allegra and Harvey, to their original forms.