Against his tightwad instincts, Scrooge must spend several surplus million dollars when he runs out of vault space to store it. After hours of what is, for him, torture, Scrooge discovers he's earned more money all the while, so he still has the surplus regardless! His response is priceless.
The boys' repeated failures with their animal calls in "The Lost Mines of King Solomon".
Seriously, everything regarding the Black Knight and his accent. Especially the ending of "The Black Knight Glorps Again":
Scrooge: (after Donald's read a letter from the Knight) Why are you reading with his outrageous accent?
Donald: Because he even writes with that outrageous accent.
The strangeness escalation of Donald's TV shows in "Guardians of the Lost Library", where the hero's vehicle always bursts into flames for no reason. Be it a car.. .A speedboat... A horse... Even a comet.
In "Dream of a Lifetime", the Inception-like dream machine makes any sound Scrooge hears during his sleep will appear as a RELATED object in his dream. Note the word "RELATED"
Every time the dream shifts and Scrooge Discovers Donald his response is: "Nephew?! What the @*%# are you doing here?!" Even when Donald runs into him as a 10 year old shoeshine boy.
In the anniversary celebration A Little Something Special, Scrooge is bored out of his mind at a celebration in his honor, held away from his Money Bin. The speaker is a tall pig, but looking down, he sees that he casts Flintheart Glomgold's shadow. His next thought balloon is presented as a rebus:
Sadly, the rebus is not continued when he learns the Beagle Boys have also joined forces with Glomgold and Magica.
It's even more hilarious when Scrooge then runs from the celebration, and Glomgold, in his disguise, desperately tries to beg the very confused Chief of Police to shoot the guest of honour down.
In The Black Knight, Scrooge tried everything he can to stop the titular Black Knight. He asked the National Guard to launch a missile strike against The Black Knight, and...
Soldier:Hmph! Scrooge McDuck just called and ordered an anti-tank missile for home delivery! What's he think we are, a pizza joint?
Officer:Push the button, man! McDuck's taxes pay for 97.3 percent of this entire installation!
The Dick Kinney/Al Hubbard story Fall Guy starring Donald and Fethry is pretty much one nine-page-long CMOF: Donald and Fethry are on a vacation by Niagara Falls, and Fethry keeps trying to go over the falls in a barrel, completely unaware that this is against the law. Through various accidents and mishaps, both the guard at the Niagara Falls◊ and Donald◊ end up in barrels and going over the falls, leaving Fethry to lament: "Everybody gets a turn but me!"
One four-page William Van Horn story has Donald and Jones trying to stop their fighting by simply ignoring one another. This goes about as well as you could expect, particularly when both of them begin to suspect that the other isn't doing his fair share of ignoring. It escalates to what looks to be a really huge fight — and then, the story's last panel cuts away to a police car driving at top speed down the road with the police radio annoincing: "Calling all cars! Calling all cars! Two neighbors ignoring one another on Elm Street! Proceed with caution!"
One story has Donald enter Bolivar (called "Bernie" in the story) in a talent contest for dogs, betting a month's dishwashing with Huey, Dewey and Louie that he'll win. When Bolivar is too lazy to be trained, Donald decides to cheat by outfitting him with a special collar made by Gyro Gearloose, one that makes Bolivar copy all the motions Donald makes. Come the talent show, Donald is all set to make Bolivar do an elegant dance on-stage — but accidentally hits his head and knocks himself out, causing Bolivar to lie completely still on the stage for the entire time he's on, to the boos and jeers of the audience. The story ends with Donald and Bolivar (still wearing the collar) both washing dishes, using the exact same motions, and glaring at one another.
An Italian comic parodied Twilight. Daisy wrote it with Brigitta as an assistant/editor. It features Donald as "Edward Duckullen" and Daisy as Daisybella. The entire comic is essentially a Crowning Moment of Funny, but here are some particularly funny things:
Magic Brigitta. Since Scrooge features into the story as Charlie Swan, she repeatedly tries to insert herself into the story and successfully woo him. Daisy no-sells every such attempt, and they get sillier each time.
Fethry Duck as Carlisle. He is The Load here, but everyone dismisses it as just him getting senile after 300 years.
Another Italian comic has this exchange between Scrooge and Gyro:
Scrooge:(storming into Gyro's workshop) Gyro! I need your help more than ever! Gyro: Don't tell me it's your spats again? Buy a new pair, for crying out loud! I've repaired your old spats twenty times! Scrooge: It's not the spats. Gyro(working himself up to a frenzy) They can't be fixed again! I'm only human! There's a limit to what I can do! Scrooge: It's not the spats! I want you to send me back in time to 1775! Gyro: What? That's all? (instantly calm again) I thought you were going to pester me about your spats again.
One story featured Grandma winning an "all-rest vacation". Gus asks if he can come with her... to give her the good example, because he doesn't think she is able to rest. He then dares her to go one single minute idle hands. Cue her staying in place cleaning the floor by using her foot and a rag.
The exact same scene is redone with the roles reversed: Grandma dares Gus to stay awake for one single minute. Cue him standing upright, eyes open, snoring.
Then Donald and Fethry come to the farm to take care of it along with Gus. As the bus with Grandma is leaving, Fethry turns to "go combing the potato tree" with a rake, Donald is knocked out with said rake, and Gus is again asleep.