Peter, a twelve-year-old living near the rural estate of Mary’s great-aunt, balances family financial struggles—evidenced by his job as a paperboy and determination to ease their hardships—with a sharp, teasing wit. He begins as a mocking rival to Mary, dubbing her “red-haired monkey” for her untamed curls and awkwardness, yet reveals a protective streak as their bond deepens. His two cats, Tib and Gib, pivotal in guiding Mary to the elusive Fly-by-Night flower, anchor his loyal nature. When Gib vanishes, Peter aids the search, though their camaraderie frays under playful jabs.

Kidnapped by antagonists Madam Mumblechook and Doctor Dee, who covet the flower’s magic, Peter endures a botched transformation experiment meant to grant permanent enchantment. The ordeal leaves him mutated: wings sprout, his hair turns blue and elongated, and his form glows with gelatinous magical residue. Retaining his wit and will, he leverages a stolen spellbook to undo the enchantment and dismantle their operations.

In the final confrontation, Peter’s courage shines as he escapes captivity, collaborates with Mary to reverse the creatures’ transformations, and destroys Endor College’s arcane machinery. Their dynamic evolves from sarcastic jabs to a bond forged in purpose, his loyalty unwavering.

His appearance—dirty blonde undercut, cornflower-blue eyes, and a blue baseball jacket with white sleeves—shifts temporarily post-transformation, his hair streaked azure and iridescent wings shimmering. He wears olive-green rolled pants and scuffed brown shoes, often tucking Tib and Gib into his jacket for safekeeping.