Valériano is an anthropomorphic green-feathered chick and one of Calimero's closest friends. He debuted in the 1992 anime series as a core member of Calimero's investigative unit, the Green Team—a name linked to his green feathers. Energetic and adventurous, he frequently carried a camera, ready to document newsworthy events, reflecting his enthusiasm for investigations and filmmaking. He typically wore a blue jacket and a signature red crash helmet with a yellow stripe, often using a skateboard for transport. His spirited nature contrasted with Calimero's calmer demeanor, creating a Red Oni to Calimero's Blue Oni dynamic. The helmet, originally an homage to motorcycle police, remained a consistent visual trait despite its backstory fading in later versions.

The 2013 CGI series reimagined Valériano as a younger character in a new continuity. He stayed within Calimero's core friend group alongside Priscilla and Pierrot, relocating to a new town where they explored inventions by Calimero's ancestor, Do Vinci. While retaining his green feathers and red helmet, his focus shifted from investigations to general camaraderie. An unexplained biological inconsistency emerged, showing both parents as white-feathered.

A dedicated spin-off series highlighted Valériano's friendship with Calimero, focusing on their joint adventures. This iteration emphasized their collaborative problem-solving, mutual support, and positive modeling, showcasing how courage and intelligence helped them overcome challenges and reinforce values.

Throughout all media, Valériano maintained consistent physical traits: green feathers, a blue jacket, and the red helmet. His relationships extended to recurring characters like Priscilla, Pierrot, and Susie. A brief romantic pairing with Rosita in the 1992 series wasn't sustained later. His personality evolved from a spirited investigator to a loyal friend, consistently retaining his energetic and supportive core.