Which Pixar Cars short features Mater pretending to be a firefighter?

Rescue Squad Mater is the Pixar Cars short in which Mater pretends to be a firefighter.

The short is part of Cars Toons: Mater’s Tall Tales, a series built around Mater telling exaggerated stories about adventures he supposedly experienced. In Rescue Squad Mater, Mater claims a heroic connection to firefighting and becomes involved in a rescue story with Lightning McQueen.

The Cars Toons shorts use a deliberately playful storytelling device: Mater’s tales are presented as memories, even though the events are often impossible or wildly exaggerated. This differs from the main Cars films, which establish the franchise’s regular continuity and character history.

Other Mater’s Tall Tales episodes use different fantasy roles. Air Mater centers on flight, Heavy Metal Mater involves music, and Monster Truck Mater concerns monster-truck competition. Those titles can make the shorts easy to confuse, but Rescue Squad Mater is the one built around emergency rescue and firefighting.