This is the first show where the opening clip isn't from later in the episode.
This is the second of four appearances Edward Asner makes in the series, the first this season. He is perhaps best remembered for his role as Lou Grant in the 1970s TV sitcom The Mary Tyler Moore Show (1970) and its spinoff, the newspaper drama Lou Grant (1977).
This is the only appearance Butch Patrick makes in the series. In a few years from the original airing of this episode, he would become a familiar face on TV, albeit hidden under lots of make-up, portraying Eddie Munster on the series The Munsters (1964).
This is the first of two appearances Grace Lee Whitney makes in the series, each time appearing as a different character. Her other appearance occurs in Line of Fire (1963). She is perhaps best remembered as Yeoman Janice Rand in the TV sci-fi series Star Trek (1966) and several of the movies that stemmed from the Star Trek franchise.
Given an uncredited bit part as a waiter in this show, Charlie Picerni is perhaps better known in the industry for his work as a stunt coordinator/director, as well as performing stunts and acting as stunt doubles for other actors. His work in Die Hard (1988) and the franchise that followed made him a star in the field of movie stunts. The actor who plays Lee Hobson in The Untouchables (1959) is in real life his brother.