The "pony car"

                                                          A "pony car" is an affordable, compact, highly styled car with a sporty or performance-oriented image.

While Ford's Mustang is generally credited as being the first "pony car", Plymouth's Barracuda came first! 

The Barracuda made it into dealers' showrooms on April 1, 1964 — a full 16 days before the Mustang.