In the first of two feature-length specials opening the second season, Flintheart Glomgold cheats Scrooge out of a business deal for an island with a valuable diamond mine by blowing up the island in half, leaving Scrooge with a worthless chunk of land. Scrooge attempts to use Gyro's time machine to go back in time and prevent this, but winds up overshooting his mark and landing back in the prehistoric age. While there, he and the rest of the gang encounter a young caveduck named Bubba, whose cave will eventually house the diamond mine in the future. Scrooge leaves a mark to keep Glomgold's claim off it for a few days in time for him to pay of the remaining debt for it. But as the gang returns to the future, they're forced to take Bubba with them. After returning to the present he must find a way to pay off the remaining money he owes Glomgold, all while dealing with his new, unwanted ward.
This episode contains examples of the following tropes.
- All Your Base Are Belong to Us: The Beagle Boys take over the Money Bin after Bubba lets them in by accident.
- An Aesop: If you stubbornly and blindly try to blame something or someone else for your mistakes instead of facing up to your own inadequacies and fixing them, you're doomed to keep failing.
- And I'm the Queen of Sheba: One of the people who refuse to believe Scrooge isn't an imposter sarcastically claims to be Quackie Onassis.
- Attack! Attack... Retreat! Retreat!: Scrooge and gang are stranded in ancient China, where Bubba the Cave Duck turns out to be a prophesied hero come to rescue the city from a cruel chancellor and a horde of barbarians. During the climax, the chancellor opens the gate and lets in the barbarian horde, who rushes past him... then immediately comes rushing back out again. The reason? The Humongous Mecha Launchpad just discovered that was hidden as an ordinary statue.
- Artistic License – Law: Even if Scrooge can't prove Glomgold blew up the island to cheat Scrooge of their deal, Scrooge could still argue in court that the deal includes both parts of the original island but the idea isn't brought up. While in prehistoric times, Scrooge leaves marks in the cave to prove that the island with the diamond mine is part of the deal.
- Been There, Shaped History: The real reason the Sphinx doesn't have a nose? A time-traveling Bubba accidentally rammed into it with Gyro's time machine.
- Being Evil Sucks: Downplayed. At the end of the episode after Glomgold has lost all of the diamonds to Scrooge, Big Time Beagle remarks how working with a crook Glomgold has left them with nothing to show for it, but it's still better than going straight, an idea that leaves them all disgusted after Bouncer brings it up.
- Body Sled: The party winds up in an underground cavern with a lot of water. They wind up using Launchpad as an impromptu raft, because his jacket is watertight (when he zips it up).
- Book Ends: In "Marking Time", when Bubba first met Scrooge, he inadvertently saved him from a Tyrannosaurus when the time machine landed on its tail. In "Ali Bubba's Cave", when Scrooge's party is cornered by a reptilian beast, Bubba inadvertently returns the favor.
- Crowd Song: "Bubba," performed by Huey, Dewey, Louie, and the rest of their class.
- Didn't Think This Through: The Beagle Boys attempt to quit working for Glomgold after they take over the money bin. However, Glomgold reminds them that even though they have access to McDuck's wealth and are holed up in the money bin, they're still wanted criminals and the police are going to bust them the second they leave, especially since they don't even have any equipment to make a getaway with the money.
- Everyone Has Standards: In "The Duck Who Would Be King" Scrooge is appalled when finding out that the Treacherous Advisor has been stealing from the people instead of earning it fair. He also calls out Sensen about sending out a child to face a horde of bandits.
- Exact Words: The deal includes the island most at "west" from Glomgold's archipelago and that's how Glomgold hopes to cheat Scrooge out of the mine by blowing up the island in half so the part without the mine will be the one that meets the description.
- Filler: "The Duck Who Would Be King" can easily be left out without disturbing the course of the story. At the end of the first episode, the protagonists attempt to return to the present after traveling to prehistoric times. At the start of the second episode, they accidentally arrive in another ancient time period and have an adventure unrelated to the main plot of the story arc. They leave this time period again at the end of the episode. At the start of the third episode, they finally arrive back in the present. None of the events from the second episode are ever mentioned again in the rest of the story arc, and episodes one and three perfectly connect to each other even without episode two in between.
- Hidden Depths: Launchpad shows an artistic side when he makes a statue of Sensen out of snow.
- Horrible Judge of Character: When Bubba is "attacked" by an out-of-control fire hose and believes it to be a monster, he asks the Beagle Boys to help him out and lets them inside the Money Bin.
- I Choose to Stay: After being sent back to One Million B.C, Bubba realizes that he prefers living with Scrooge in the present so he and Tootsy go back.
- I Lied: After getting a diamond worth a little more than what he owes Glomgold, Scrooge rushes to deliver it. A little less than 12 seconds before Glomgold says he has exactly this time to pay, Scrooge delivers it and Glomgold reveals that he lied and Scrooge missed the deadline. Scrooge checks upon his pocket watch and realizes he did miss the deadline.
- Ill-Timed Sneeze: When the gang hide behind mushrooms from the large creature, it is revealed that Launchpad is allergic to mushrooms. Fortunately, the boys stop him from sneezing and blowing their cover. Unfortunately, Scrooge sneezes instead.
- Laser-Guided Karma: After Glomgold manages to keep Scrooge from paying off his debt before the deadline is up, he tosses away a diamond which results in the impact from it causing a cave-in. Rubble from the cave-in falls into a geyser causing it to explode, which causes all the diamonds in the mine to get blown from Glomgold's island to Scrooge's, leaving him with nothing.
- The Load: Bubba is personally viewed in-universe as this by Scrooge, due the incidents he causes from being unfamiliar with the present day. However, a lot of the incidents result from Scrooge directly trying to brush Bubba away onto anyone or anything.
- Mistaken for an Imposter: In order to keep Scrooge from getting any money from one of his banks in order to pay off his dept to Glomgold, the Beagle Boys impersonate him via telephone and tell all of the bank managers that there is a phony running around, giving them instructions to use to prove if he's the real deal. Since the actual Scrooge is unaware of this, everyone at each bank thinks he's an imposter, with one man eventually calling the police and getting him arrested.
- Multi-Part Episode: Like "Treasure of the Golden Suns" and the future "Super DuckTales" the episode is edited into five parts in reruns:
- Part 1: Marking Time
- Part 2: The Duck Who Would Be King
- Part 3: Bubba Trubba
- Part 4: Ducks on the Lam
- Part 5: Ali Bubba's Cave
- Mythology Gag:
- Scrooge having ten million dollars in his top hat is one to the comicbook story "The Heedless Horseman", where he buys a racehorse for that amount.
- Gyro's Time Machine is fueled by a substance named Bombastium that needs to remain frozen to work and is shaped like popsicles (they taste like it too, but if you try to eat one, you get sent to a random spot in time for a few seconds). In the comics, Bombastium is a unique element that can produce any type of ice cream with just a single gram and a barrel of water.
- Necktie Leash: A non-romantic example; Scrooge grabs Launchpad's scarf and uses it to drag him into the house when he's trying to talk him into watching Bubba. While it doesn't have the usual romantic overtones, it still plays into the power dynamic aspect of the trope, given that Launchpad works for Scrooge and has an accommodating enough personality that the older duck can usually talk him into following his plans pretty easily.
- Nobody's That Dumb: After the triplets and Mrs. Beakley have both taken turns watching Bubba (and chaos has ensued), Scrooge tries to dump him off on Launchpad. The pilot refuses, saying that he's dumb but not crazy.
- Opinion Flip Flop: Scrooge tries to get Launchpad to watch Bubba while Gyro fixes the time machine, even telling him that he can have any price he wants for the service. Launchpad refuses, saying he can't be bribed...until Scrooge offers him a new scarf, at which point he immediately agrees.
- Papa Wolf: Scrooge calls out Sensen for planning to let The Chosen One handle the bandits, given that the chosen one is just a child. This is particularly striking considering that he doesn't really like Bubba at this point.
- Pyrrhic Victory: Glomgold wins and gains complete control of the island and the mine, but he ultimately loses the diamonds, all of which go straight to the island Scrooge still owns.
- Race Against the Clock: Scrooge must repay the rest of the money he owes Glomgold for the island and its diamond mine after the initial downpayment within three days, or else Glomgold will have full possession of it again. Notably, he ultimately fails in the end, but fate still intervenes and rewards him.
- Set Right What Once Went Wrong: Scrooge and his friends initially travel back in time to prevent Glomgold from blowing up the island.
- Shout-Out: Glomgold says to Bubba, "I'll get you, laddie, and your little dinosaur too!"
- Spontaneous Choreography: When Huey, Dewey, and Louie bring Bubba with them to school, it results in the entire classroom bursting into a musical number. However, all the commotion causes the principal to burst in which leads to all the students getting detention and Bubba getting kicked out.
- Unwitting Instigator of Doom: Scrooge had never planned to take Bubba back with him, but he took his presence relatively well before Gyro suggested that the changes to the timeline might cost Scrooge his fortune.
- Villainous Breakdown: After the mine explodes and all the diamonds end up on Scrooge's land, Flintheart breaks down and starts pounding on the ground like a bearded toddler over being foiled again!Flintheart: Scrooge always wins! IT'S NOT FAIR!!
- When the Clock Strikes Twelve: Scrooge must pay the last installment before Friday noon, or he won't keep the island he bought from Glomgold.
