Animal Crackers (1930)

Continuity mistake: In the very first scene, after the lead flunkie finishes his song, he turns around to speak to Margaret Dumont. When he turns back, look closely at his waistcoat - it's completely different.

Grace Carpenter: Well, Sis, it looks as if we yield the social honor of the season to Mrs. Rittenhouse.
Mrs. Whitehead: Well, isn't there something we can do?
Grace Carpenter: We might shoot ourselves.
Mrs. Whitehead: I'd rather shoot Mrs. Rittenhouse.

Trivia: Near the end, during their extended nonsense bit about the stolen Beaugard painting, both Chico and Groucho were rapid-fire ad-libbing so heavily that they became irritated with one another. In fact, by the time Groucho ad-libbed, "I'd buy you a parachute if I thought it wouldn't open," he was getting really pissed off at Chico's faster and funnier come-backs. Almost instantly, Chico shot back, "Hey, I already got a pair-uh-shoes!" (which was, again, funnier than Groucho's parachute line). At that point, Groucho snapped and sprang into some improvised physical comedy, falling backwards across the card table and elbowing Chico right in the face, perhaps on purpose. Genuinely shocked from the blow, Chico recoiled wide-eyed, looked toward director Victor Heerman off-camera, and angrily exclaimed, "He's crazy!" (referring to Groucho).

Charles Austin Miller