The Three Caballeros are dead and in the underworld. Xandra visits Charon to get them back while April, May, and June set up a seance (due to what Daisy had done in the previous episode).
- Ass Kicks You: The giant Sheldgoose-monster sits on the Caballeros. José calls it "the most unpleasant experience of [his] life".
- Back from the Dead: The Caballeros, Felldrake, Sheldgoose, and Leopold all return to the land of the living.
- Big Red Devil: The boss of the underworld turns out to be a scaled up version of Donald's shoulder devil.
- Blow You Away: The Tengu has the power to create tornadoes.
- Body Horror: Ghosts are capable of inflating body parts. The Caballeros do this during the climax, along with Sheldgoose's family, who all fuse together. This is almost certainly a Mythology Gag to Donald's failed attempts at returning to normal size after shrinking in the original film.
- Body of Bodies: Sheldgoose's ancestors fuse into one of these after inflating their various body parts.
- Brick Joke: In the episode "World Tree Caballeros", Felldrake tells the Caballeros he'll see them in Hades. At the end of this episode, he tells them "It was nice seeing you in Hades!"
- Celestial Bureaucracy: The Caballeros have to take a number and wait before being analyzed. They end up taking the exit. Sheldgoose manages to exploit this by rising up the ranks and making the Caballeros do paperwork in order to return to Earth.
- Dark Is Not Evil: The Underworld is not hellish and some of its residents seem perfectly happy there. Charon has updated his grim persona to make more money and to actually have fun with his job. And even Satan is simply doing his job.
- Deader than Dead: Clinton implies this what happens when a ghost is killed by a yokai.
- Don't Fear the Reaper: Charon presents himself as a upbeat captain of a cruise ship rather than the grim ferryman he was in the past.
- Eat Brain for Memories: A non-lethal version. Ghosts are able to tap into their brain to create a "memory juice", which allows the drinker to see their memories.
- Groin Attack: Donald uses his enlarged foot to kick the Sheldgeese between the legs. This is also inverted as the Caveman Sheldgoose (who's the crotch) bites him back.
- Inconvenient Summons: The Nieces manage to summon Panchito's ghost from the Underworld with a Spooky Séance just as The Caballeros are forming a plan to fight the Tengu.
- Inflating Body Gag: Clinton demonstrates how ghosts can blow themselves up like balloons. The Caballeros later use this to their advantage when fighting the Tengu, as do the Sheldgeese in the final battle.
- Losing Your Head: Clinton's cousin Clara had this happen to her, as she's seen walking carrying her head around.
- Mythology Gag:
- Clinton Coot has some Scrooge McDuck figurines in the cabana, actually based off classic poses from the comics.
- The ability to inflate body parts is a reference to the "black magic" scene from the original movie.
- Non-Indicative Name: Clinton Coot is actually a duck, not a coot.
- Ramming Always Works: Xandra uses Charon's cruise ship to ram into the Sheldgeese.
- Shout-Out:
- While combining into one being, Sheldgoose shouts "And I'll make the head!".
- The Weird Moon in the Underworld has a face heavily resembling Jack Skellington's.
- Spooky Séance: Because Daisy broke their only method of contacting the Cabs normally, the nieces try one to get at least one of them back from the Underworld in this way.
- Tengu: The gatekeeper of the gate that separates the Underworld and the land of the living is a Karasu Tengu. However, he is erroneously called a falcon-based creature over the proper crow-based one.
- Yōkai: A variety (made up of a Karakasa, a Kappa, and an Oni) lurk about in the dark alleys of the Underworld City, with a Tengu warrior guarding a gateway out of the afterlife that leads to the foothills of Mount Fuji. Unlike the other inhabitants of the Underworld, they are not ghosts, and have the ability to kill them.
