Leonard is a green frog sporting chubby cheeks, large black eyes, and prominent nose-holes, typically clad in a yellow and white jacket over a dark shirt, dark trousers, and white sneakers. His sentimental, romantic nature leads him to sing with the rain, while his demeanor balances playful energy and childishness with a tendency toward overreaction to minor incidents. He views Moon as an older brother figure, interacts closely with Sally and Edward in the "tiny little trio," and enjoys Cony’s care while remaining cautious around her. His media roles shift between LINE TOWN, where he admires Moon, and the Netflix series, where he serves as DJ in Moon’s band. As one of the youngest characters alongside Sally, Edward, and Choco, Leonard skips the tadpole stage despite his species and debuted in 2014, excluding him from the LINE OFFLINE series.