An episode with Jerry Lewis on the panel featured a guest who was...a bit rotund. Lewis jokingly suggested that the lady made diet pills — which turned out to be her occupation. note Incidentally, in the same episode, between segments, he turned serious to pitch for donations for the Muscular Dystrophy Association, the organization for which he'd become synonymous. After his brief monologue, it was right back to the fun.
Jerry Lewis: But doesn't she take them at any time?
John Daly was noted for, if the panel asked a question that could be answered "yes" or "no" depending on interpretation, first conferring with the guest and then giving a convoluted speech which almost invariably raised more questions than it answered. However, when the famously verbally dextrous actor and singer Danny Kaye appeared as a guest on the 5 November 1961 episode, he turned the tables on Daly by asking a ridiculously convoluted (and deliberately content-free) question:
(the panel have established that self-employed guest Harry Ellswood Jr. makes a product that can be "used up" but is not eaten, drunk, or held in the mouth without being swallowed)note The product in question: balloons. Danny Kaye: In this product, does the chemical content insofar as the letter of the instance of the product, can you, in turn, with a degree of honesty, feel that there has been, not- not concerning those people who generally don't use it, but would there be - would there be insofar as, knowing a group of people as seated here, could you? (laughter from audience, panel, Daly, and Ellswood) Harry Ellswood Jr.: Could you please repeat the question? (more laughter) Danny Kaye: I'd be happy to. Conference! (puts his arms around Dorothy Kilgallen and Arlene Francis and kisses each of them on the cheek) I don't really want a conference, I want smooches!
During the Steve Allen era, after the question "Is it bigger than a breadbox?" had become almost standard during the interrogation of guests, the producers used up the last few minutes of one episode by sending out Pete Burg, who made... breadboxes. When Dorothy Kilgallen, having established that Burg dealt with a product that would be found on the ground floor of a two-story home, asked, "But it's not larger than... a breadbox?", the audience fell about laughing. As a breadbox is not technically larger than itself, questioning passed to Steve Allen, who put two and two together.
Steve Allen: I'm gonna take the- the first stab in the dark in a, in a year, is it a breadbox, by any chance? (laughter from audience, panel, and John Daly) John Daly:(pointing at Steve Allen) What does Mr. Burg do with breadboxes? Steve Allen: He hides in them!
After stepping down as a regular, Steve Allen made a number of return appearances as both a guest on the panel and a mystery guest. On the 4 October 1964 episode with Buddy Hackett as a guest panellist, Allen was the episode's mystery guest, but things didn't quite go according to plan thanks to a verbal slip from John Daly:
Dorothy Kilgallen: Are you a performer in show business? Steve Allen:(loud whisper) Yeeeessss. John Daly: Mr. Allen- I- (laughter from panel as Daly looks embarrassed) Mr. Cerf. Bennett Cerf: I'll make believe I didn't hear that. John Daly: You can't. I'm not kidding... Bennett Cerf: Are you a comedian? Steve Allen:(in his normal voice) I'm not as funny as John is right now! (laughter and applause; Dorothy Kilgallen and Bennett Cerf remove their blindfolds, but Arlene Francis and Buddy Hackett leave theirs on) Steve Allen: All right, Buddy, three guesses, who is it? (Buddy Hackett starts to remove his blindfold) Your time's up, Buddy!
Ed Sullivan:(disguised voice) Mr. Dah-ly, why they wear masks? John Daly: Why they wear masks? So they can't see what's going on. Ed Sullivan: Then I wear mask too. (produces a caveman-like rubber mask and puts it over his head, derailing Daly's attempt to explain his last answer)note A similar mask appeared in several episodes of The Dick Van Dyke Show.
Early in the syndicated run, panelist Anita Gillette accidentally introduced Allen Ludden as "Allen Funt" (host of Candid Camera). Moments later, after Wally Bruner was introduced and took his seat, he welcomed the home audience, "Welcome to Candid What's My Line?"
During the Larry Blyden era, a 1973 episode saw, following a segment about a pizza maker, guest panelists Gene Rayburn and Alan Alda toss pizza dough rounds in the air ... only for one to be tossed SO high it landed in the overhead lights and didn't come down. The audience was uproarious in their laughter as the cameras focused on the round being stuck high above the stage.