Cars introduced Mater before he appeared in Cars 2 and Cars 3.
Mater is the rusty tow truck who lives in Radiator Springs and becomes Lightning McQueen's closest friend. He first appears in Pixar's 2006 film Cars, where Larry the Cable Guy provides his voice. Mater's humor, loyalty, and exaggerated stories made him one of the franchise's most recognizable characters.
After the original film, Mater became a central character in Cars 2. That sequel places him at the center of an international spy adventure involving Lightning and the World Grand Prix. He also returns in Cars 3, where the story shifts back toward Lightning's racing career.
Mater's Tall Tales is a separate series of short films and was not his feature-film introduction. Cars 2 likewise was not his first appearance, even though it gives him an unusually prominent role. His home is Radiator Springs, and his job there is operating a towing service.