The Fairy, also called the Fairy of the Oak Tree or the Fairy with Turquoise Hair, has fair skin, long wavy turquoise hair, and turquoise eyes accentuated by blue eye shadow. She wears a white gown with a pink bow at the waist, a large white cloak fastened by a gold button and revealing blue fabric underneath, pink earrings, white gloves, and a medieval-style princess hat. She wields a wand shaped like a tree branch for casting spells.

She inhabits an oak tree and intervenes to grant Geppetto's wish for a son by bringing his wooden puppet, Pinocchio, to life. To grant Pinocchio full humanity, she sets one condition: he must prove his kindness and integrity. Throughout Pinocchio's trials, she serves as his mentor and protector, imparting moral lessons through enchantments. When Pinocchio lies, his nose grows long; only when he confesses his deceit do summoned woodpeckers peck it back to size.

Her interventions are frequent: she rescues Pinocchio after antagonists hang him, heals him after his transformation into a donkey, and aids his escape from enslavement under the puppeteer Sneeroff. She also guides him toward self-sacrifice, prompting him to brave danger gathering a rare herb to cure ill children.

In the climax, she shields Pinocchio from soldiers attempting his execution. This act directly enables his final transformation into a human child, rewarding his proven courage and compassion. It completes her guardianship, as she declares her inability to appear to him again now that he is human.