In Wacky Races, Penelope Pitstop drives the Compact Pussycat, a pink, stereotypically feminine car. Consistent with this theme, she has blonde hair tied into a ponytail and wears a bright pink racing uniform with white gloves, maroon tights, and white go-go boots. She is described by the race announcer as the "Glamour Gal of the Gas Pedal". As Wacky Races is inspired by The Great Race, Penelope is inspired by the Maggie DuBois character (played by Natalie Wood in the film).
According to Iwao Takamoto, Penelope was an afterthought in the development of Wacky Races. Joseph Barbera requested that a woman be added among the racers, so Takamoto and Jerry Eisenberg designed Penelope and her car in about two hours.
The Perils of Penelope Pitstop, a spinoff from Wacky Races which features Penelope as the lead character, is set in the 1920s. Penelope is a traditional "damsel in distress" stock character as in the old serial The Perils of Pauline. Her catchphrase is "Help, help!" (spoken in an affected non-rhotic upper-class U.S. South accent, and pronounced "HAY-ULP"). She displays a curious combination of ingenuity and helplessness. She often figures out clever ways to get out of perils and is very athletic; if any sport happens to be mentioned, it is revealed that she was the women's champion in said sport in college. Nonetheless, when her nemesis the Hooded Claw, voiced by Paul Lynde (who, unknown to her, is her guardian Sylvester Sneekly) grabs her, she is somehow incapable of doing anything other than yelling for help. She will occasionally flee from his clutches, running in an unusual goose-stepping stride. Also in the background helping her out of her perils are the minuscule Ant Hill Mob and trusty old classic car Chuggaboom (which is actually based on another team from Wacky Races).
In the series, Penelope's car is called the Compact Pussycat. Bearing the numeral 5 on the sides, it is a pink racecar, with front bumpers that look like a pair of red lips with lipstick on them. It has an umbrella on the top and is equipped with an assortment of beauty supplies, making it essentially a beauty parlor on wheels.