The Flintstones was still very popular when the fourth season opened with what may the most famous single episode: "Ann-Margrock Presents." Ann-Margaret, who had become an overnight sensation in "Bye Bye Birdie" (1963), provided the voice for her caricature. During the 1962-63 season, the series had made cartoon history when Wilma became pregnant. According to Joe Barbera, Wilma and Fred were originally going to have a son, Fred Jr., but potential profits from doll and toy sales changed the offspring to a girl. (Ideal's Pebbles doll earned almost $20 million in 1963, and General Mills introduced the "Pebbles" sugar cereal.) During the fourth season, the Rubbles adopted a super-strong baby boy named Bamm-Bamm, who had been left on their doorstep, and provided a playmate for her.

Ann-Margaret's appearance led to a spate of celebrity caricatures and spoofs of other TV shows, including Candid Camera ("Peek-A-Boo Camera") and Sing Along with Mitch ("Hum Along with Herman" in "The Flintstone Canaries"). "Ladies Night at the Lodge" feels like an old I Love Lucy episode, as Betty and Wilma sneak into the Water Buffalo Lodge and get paddled for their pains. Many observers noted The Flintstones was essentially Jackie Gleason's The Honeymooners in caveman costume, but the TV parodies and the reliance on such gimmicks as aliens producing robotic versions of Fred in "Ten Little Flintstones" make it clear that the show was running out of gas. (Unrated, suitable for ages 7 and older: cartoon violence) --Charles Solomon