Which popular 1960's American car was affectionately known as "The Goat"?

The popular 1960s American car affectionately known as “The Goat” was the Pontiac GTO.

Pontiac introduced the GTO for the 1964 model year as an option package for the Pontiac Tempest. It combined a relatively compact car with a powerful 389-cubic-inch V8, upgraded suspension, and performance-oriented equipment. That formula helped establish the modern American muscle-car market.

The name GTO came from the Italian phrase “Gran Turismo Omologato,” meaning a grand touring car approved for racing competition. Pontiac’s use of the name was inspired by Ferrari’s 250 GTO, although the Pontiac was a very different kind of vehicle: a mass-market American performance car with a front-mounted V8 and rear-wheel drive.

“Goat” became a playful pronunciation of GTO and eventually turned into the car’s best-known nickname. The nickname belongs especially to the classic 1960s and early-1970s GTOs, not to every Pontiac model. A later GTO revival appeared for the 2004–2006 model years, but enthusiasts generally use “The Goat” when discussing the original muscle-car era.