What was the first Cars Toons short released by Pixar?

Rescue Squad Mater was the first Cars Toons short released by Pixar.

It premiered on October 27, 2008, as the opening installment of the Cars Toons series. The short follows Mater as he imagines himself serving as a heroic fire truck and rescue vehicle, continuing the character's habit of telling elaborate stories about his past.

Cars Toons is a series of animated shorts built around Mater and Lightning McQueen. The episodes are deliberately lighter and more exaggerated than the feature films, often presenting Mater's claims as playful tall tales rather than literal additions to the main story.

The first short is sometimes confused with Mater the Greater, which was released later in 2008. Rescue Squad Mater established the series before later installments explored Mater as a stunt performer, astronaut, or secret agent.