In this pilot, Imogene Coca's character was named "Shag." When the producers were made aware that "shag" is a slang vulgarism for sex in the U.K., they changed her name to "Shad." But it was too late to incorporate the change into this pilot, which aired as the premiere episode. The animated opening titles of early episodes continued to read "Shag" despite her character being called "Shad."
Mike Mazurki, who played kill-crazed caveman Clon, was no stranger to his stone-aged role, having earlier played the Wasatchi caveman Ugh-ug in It Takes a Heap o' Livin' to Make a Cave a Home (1962).