The 1955 film:
- The local police officer stops by to chat with Mrs Wilberforce, but since the gang have told her to drive him away without making him suspicious, she doesn't invite him in as she normally would. Instead she blurts out all the excuses the gang had suggested— starting out with "You can't come in here without a search warrant!" and ending with "Now would you please buzz off!" (thanks, Harry).
- Mrs. Wilberforce briefly forgets the suitcase (with the loot in it) that the gang is using her to pick up.
[When driving past the police station, they see their case of money sitting in the doorway]Harry: I don't believe it. I don't believe it!Louis: Shut up.One-Round: It's just... sitting there. Look, couldn't we...?Professor Marcus: No one, I hope, is going to suggest that we steal it.
- One-Round's losing it when he thinks someone's killed Mrs. Wilberforce ("I said nobody was to do Mrs. Lopsided!"), culminating in a brawl that comes to a shocked stop when Mrs. Wilberforce appears at the foot of the stairs (she was asleep).
Mrs. Wilberforce: What are you doing? And who is "Mrs. Lopsided," may I ask?
- Professor Marcus' death by railway semaphore. In the stage version this is part of a Chekhov's Gag; characters keep treading on his scarf, which he then struggles to pull free. At the close, Marcus flees down a train tunnel, only to find his scarf caught yet again and... well you can guess what happens next.
- The ending. Thanks to the implausibility of Mrs. Wilberforce's story, the police don't believe a word of it. So she gets to keep the money, just as Professor Marcus had said when trying to convince her not to go to the police!
- The entire gang (except the Major) piling into a telephone box to find out what's happening at the station.
- The Brick Joke of Mrs. Wilberforce forgetting her umbrella because she doesn't like it very much.
- Louis grumbling about Mrs. Wilberforce's constant interruptions, culminating in "Give the parrot his medicine!" Then he realises what he just said and does a verbal Double Take: "Give the parrot his medicine?!"
- Also, what happens when the gang attempt to give the parrot his medicine. One-Round ends up stuck in a chair, Harry gets his finger bitten, and Professor Marcus comes home to find the Major and Louis on the roof.
- After Mrs. Wilberforce picks up the money for the gang (without knowing what it is), Professor Marcus says, "What Could Possibly Go Wrong?" Glad you asked, Professor...
- Mrs. Wilberforce realises the truth about the gang just before her friends arrive for tea. Louis says they should kidnap her. One of her friends arrives. Louis says they should kidnap both of them. Then Mrs. Wilberforce's other friends arrive.
Harry: What should we do? Charter a bus?
The 2004 film:
- The General's plan to murder Ms. Munson backfires hilariously when a cuckoo clock startles him into swallowing his lit cigarette, then he tries to drink the water containing her false teeth, which makes him bolt out in terror, tripping over the cat and breaking his neck as he falls down the staircase. All set to an old-timey gospel tune.
- Professor Dorr's Oh, Crap! reaction when Lump tries to think for himself.
- Ms. Munson's barrage of slaps to Gawain's face upon hearing a sample of his "hippity-hop" language.
- "Professor...I can't really play the buttsack."
- Anything Gawain says and/or does:
Gawain: Can't stop shittin', can't stop talkin' about shittin'...
- This bit, after Garth tells him about his IBS and won't stop talking about it:
- When the bomb goes off, he and a security guard stare at each other for a few seconds, and Gawain breaks the silence by asking him: "Did you just fart?"
- The director of the dog food commercial that Garth is working on refers to the ASPCA rep as that "humane fucker". Then Garth gives the passed-out dog CPR.
- Some of the professor's unorthodox behavior is good for a laugh, like when he first tours the basement and abruptly shouts "Whih whih whih!"- he explains he's testing the acoustics.
The 2011 stage version:
- The Running Gag of Harry getting repeatedly hit in the face with the blackboard.