In Pixar’s Cars: Mater’s Tall Tales segment Rescue Squad Mater, Mater becomes a fire truck.
Mater’s Tall Tales is a series of short films in which Mater tells increasingly extravagant stories about adventures he supposedly experienced. In Rescue Squad Mater, he imagines himself serving as a firefighting vehicle and taking part in an emergency rescue. The short plays with the contrast between Mater’s ordinary identity as a tow truck and his heroic self-image.
The series is built around a recurring joke: Mater confidently describes events that sound impossible, while Lightning McQueen often appears to confirm them within the story. The shorts expand the Cars world without following the same structure as the feature films.
Mater remains a tow truck in the main Cars films, so “tow truck” is a tempting but incorrect answer for this particular segment. Rescue Squad Mater is a transformation within one Tall Tales story, not a permanent change to his character or occupation.