James "Jimmy" Murray, known as Cousin Jimmy, lives at New Moon Farm in Blair Water with the Murray family. He is cousin to Elizabeth and Laura Murray, making him Emily Byrd Starr's first cousin once removed. A childhood accident, where Elizabeth accidentally pushed him into a well, caused a lasting brain injury. This led some in the community to call him "Jimmy Murray the Fool," though the injury primarily resulted in childlike behaviors and occasional "queer spells" of disorientation or unusual speech.

Despite this, Jimmy works the land at New Moon, earning his room and board. He maintains an optimistic view, brushing off others' perceptions by attributing them to his poetic nature and lack of conventional worries. Gardening sustains his resilience, providing therapeutic purpose and stability.

He forms an immediate, strong bond with Emily upon her arrival, becoming an early source of kindness and emotional support. Jimmy shows perceptiveness about her creative aspirations and struggles, offering gentle guidance. His own artistic expression emerges through spontaneous poetry, recited outdoors or during farm chores like boiling potatoes for livestock. This creativity reveals his sensitivity and depth.

His relationship with Elizabeth remains complex; her actions caused his injury, yet they coexist through mutual familial obligation. Jimmy exhibits flashes of emotional volatility, especially when faced with condescension about his intellect. However, his fundamental compassion is clear in his steadfast loyalty to Emily and the Murrays, and his intuitive grasp of the household dynamics.

Across adaptations, Jimmy retains these core traits. The narrative consistently portrays him as an integral New Moon figure whose quiet wisdom and artistic inclinations offer Emily companionship and validation. His background emphasizes resilience amid adversity, with gardening and poetry symbolizing enduring creativity despite marginalization.