The episode opens with the Simpsons family buying Christmas trees early on Halloween, dressed in Halloween costumes, where they are locked in and ambushed by Sideshow Bob, the Leprechaun from "Treehouse of Horror XII", the ghost of Frank Grimes, and Kang, all seeking revenge on the family. Then, in a couch gag parodying Planet of the Apes, viewable with Google Cardboard for special content, the Simpson family are captured on a planet populated by living couches, before being rescued by their generic brown couch.
It contains the following segments:
- Dry Hard: In a parody of The Hunger Games and Mad Max: Fury Road, Mr. Burns controls the last of the water supply in a severely drought-stricken Springfield, and forces the children to battle each other to the death in a dome, with the prize being the chance to spend a day swimming in his personal reservoir.
- BFF R.I.P.: When Janey, Sherri & Terri, and Lisa's therapist all die under mysterious circumstances, Lisa realizes her imaginary friend from the past, Rachel (voiced by Sarah Silverman) has returned, seeking to kill anyone close to her so she could be Lisa's only friend.
- Moefinger: In a parody of Kingsman: The Secret Service and James Bond, after Bart is saved from Jimbo, Dolph and Kearney by Moe, he reveals that he and his regular barflies are actually secret agents, and they want him to replace Homer, their top agent who was thought to have previously died, but has a new identity as a supervillain.
Tropes features:
- 13 Is Unlucky: Lisa counts to 13 in her hide-and-seek game with Janey, before the latter is killed by Rachel.
- Advertised Extra: Russ Cargill was shown in the trailer alongside Bob, Kang/Kodos, Frank Grimes' ghost, and the Leprechaun out for revenge on the Simpsons. He's nowhere to be seen in the actual episode.
- Anyone Can Die:
- In "Moefinger", well, Homer, the angry mob and the secret agents, anyway, all dead except for Bart.
- Implied at the end of "Dry Hard" when it shows only Lisa and Marge alive during the new ice age.
- Ascended Extra: Lisa previously mentioned having an imaginary Jewish friend named Rachel Cohen in Season 15's "Today, I am a Clown". She appears as the antagonist of "BFF R.I.P.", seemingly confirmed by Lisa's old drawing of Rachel's Jewish wedding. Also crosses into Adaptational Villainy.
- Asshole Victim:
- Three of the villainous "Furious Four" in the title sequence are quickly killed by Maggie. Grimes escapes because he's already a ghost.
- In "BFF R.I.P.", Sherri and Terri only wanted to befriend Lisa due to Janey's death making her "interesting", and the tombstone squashing them was far more cartoonish than Janey's horrific demise.
- Jimbo's gang in "Moefinger" implied they were intent on actually killing Bart rather than simply beat him up before Moe steps in and mops the floor with them.
- Big Damn Heroes: Moe saves Bart from being killed by Dolph, Jimbo and Kearney in Moefinger by killing them with a beer glass, coaster and his apron.
- Biting-the-Hand Humor:
- After the 600 episode countdown, Frank Grimes says that "In Hell they make you watch them all in a row."
- The list of canceled Fox shows included in the final song includes The Critic and Futurama, both of which share producers and staff members with The Simpsons.
- Bond One-Liner: In the James Bond parody, naturally.Moe: [takes out Kearny with a beer mug] Guess I should have used a coaster. [takes out Dolph with a coaster]Carl: [about his mission to Prague] I cancelled a few "Czechs".
- Breaking the Fourth Wall:
- After the title screen, Frank puts his head back on and questions the audience about "stopping these people". The screen is then filled with clips from all the episodes so far and a counter goes from 0 to 600. Frank then says to the audience that in Hell, they make you watch all the episodes in a row.
- Another moment happens during "Moefinger." When Moe opens a secret entrance under the pool table, Bart says that he didn't know it could do that, and Moe remarks it was possible with "Halloween show money."
- Call-Back: In "BFF R.I.P.", Drew Carey wasn't actually supposed to be at Sherri and Terri's funeral, but delivers their eulogy anyway, just like how in "Bart the Fink", Bob Newhart was actually waiting for another funeral, but delivers the eulogy for the presumed-dead Krusty's funeral, even though he never knew him.
- The Cameo: Laura Powers from Season 4's "New Kid on the Block" briefly appears at the beginning of "Dry Hard".
- Captivity Harmonica: Bart and Lisa escape the prison in a bin full of used harmonicas.
- Character Check: "BFF R.I.P." revives incidental schoolkid Janey in her original role as Lisa's best friend in the earliest seasons of the show, before Lisa was turned into a social outcast with a Friendless Background.
- Cool and Unusual Punishment: In the opening sequence, the ghost of Frank Grimes claims that in Hell they force you to watch every Simpsons episode in a row.
- Lisa threatens this to Rachel by using her Reality Warper powers against her.
- Couch Gag: The first one on a Halloween Episode since "Treehouse of Horror X".
- Curb-Stomp Battle:
- Just as the "Furious Four" are about to strike, Maggie pulls out a stiletto and decapitates them all with one stroke.
- Moe easily dispatches the bullies in "Moefinger". Of course, it's one trained agent versus a few 13-year-olds.
- Deader than Dead: Subverted and possibly defied. The ghost of Frank Grimes is beheaded by Maggie in the title sequence, but because he's a ghost, he can reattach his head with no problem. His fellow villains aren't so lucky, though.
- Dirty Coward: Millhouse is proud of it too when he kills Nelson In the Back.
- Didn't Think This Through: Mr. Burns may have been hoarding all the water in the reservoir for himself but the fact remains it was in a reservoir. When the rebels blow the wall, all the water drains away, leaving them with nothing.
- The Farmer and the Viper: The Couch rescues the Simpsons only for Homer to hit it with a rock and sit on it.
- Faux Horrific: 'Sergeant Sausage' exploding may have seemed gruesome, but that's basically what happens anyway when you cook a sausage or hot dog without cutting slits in it first, as he Lampshaded.
- Fun with Acronyms: Chief Wiggum tries to invoke this, but is bad at thinking them up.
- Gorn: At the end of "Moefinger", Bart stabs Nelson with a sword, then pulls it downward to tear his stomach open and causes his intestines fall out for all of us to see.
- Gory Discretion Shot: Much like Homer's head meeting the business end of a food disposal, it was probably best we didn't see Janey hacked to bits by the lawnmower.
- Idiot Ball: The Springfielders who kept reelecting Mr. Burns in spite of how he hogs the water supply for himself.
- Imaginary Friend: Rachel (for Lisa), Sgt. Sausage (for Homer).
- Kids Are Cruel: Bart just picking up and dumping Lisa's scrapbook labeled "Childhood Treasures" in the trash for no reason.
- Legion of Doom: The "Furious Four"
- Limited Wardrobe: When the police are searching Lisa's room, her closet is shown having multiple identical red dresses.
- Loose Canon: Treehouse of Horror episodes are considered non-canon to the main show. However, this episode does establish Sherri and Terri having a pair of older twin brothers named Jerry and Larry, as well as their parents Barry and Mary.
- Monumental Damage: Homer's lava flow takes out the White House, Mt. Rushmore, the Taj Mahal, the London Eye, then consults a guidebook on "Earth's Greatest Landmarks" for its next target.
- Nice Job Breaking It, Hero: Lisa at one point tells Rachel that Marge was right to make her get rid of her imaginary friend. This puts her mother on Rachel's hit list.
- Not-So-Imaginary Friend:
- Rachel from "BFF R.I.P.", who is real enough to kill Lisa's other friends.
- Homer's imaginary friend 'Sergeant Sausage' comes to the rescue, but is quickly dispatched by Rachel.
- Obfuscating Stupidity: "Moefinger" revolves around Moe's Tavern being a front for a Bond-style spy operation and all the barflies being highly skilled professional agents who pretended to be dumb drunks.
- Off with His Head!:
- Maggie's Curb-Stomp Battle of the "Furious Four" leaves them all beheaded, with their human, leprechaun and alien blood mixing to spell out the title in purple... Frank Grimes reattaches his head without issue due to already being a ghost.
- Implied to have been done by Barney with his quote to Ned, "That's the kind of noggin we need leading this rebellion", followed by Ned's decapitated head being used as Barney's hood ornament on his "Plow King" truck.
- Bart pulls this on several of the angry mob in "Moefinger", twisting Sideshow Mel's head until it pops off like a wine cork and using Ranier's necklace like a garrote to slice his head clean off.
- Pun: The "Moefinger" segment ends with Bart "having a little Sherri".
- Reality Warper: Lisa's imagination is powerful enough to create an imaginary friend capable of killing real people. When Bart points this out she realizes he's right and has no trouble creating a motorcycle. And then she threatens to use her imagination to turn Rachel into a stressed out mother.
- Right-Hand Cat: Homer has one in "Moefinger", which is responsible for the one scar on his face.
- Sdrawkcab Name: Homer's business cover is named Remoh Enterprises. When Moe points out that it's just Homer's name spelled backwards, Homer's response implies that it was purely accidental.
- Shout-Out:
- The title "Dry Hard" is a play on Die Hard.
- In the title segment, Homer is dressed as a trash-can version of Bender from Futurama. Bart's costume resembles Rodan.
- During the 2nd The Hunger Games segment, which has suddenly turned into a Mad Max: Fury Road parody, Drederick Tatum is driving a 2-wheeled vehicle not unlike Axel from the Twisted Metal games.
- Burns dumps water on himself ala Flashdance.
- Homerish drinks Logan's Rum.
- Song Parody: A parody of the titular song from Goldfinger plays over the end credits.
- Summon Bigger Fish: In "BFF R.I.P.", Homer tries to fight Rachel by bringing back his childhood imaginary friend, Sergeant Sausage. Unfortunately, Rachel defeats him easily. But as an imaginary friend, he's Not Quite Dead. And the microwave battle does buy Lisa just enough time to defeat Rachel herself.
- Sure, Let's Go with That: Homer pretending he chose the name Remoh for his business cover because it's his name spelled backwards. He actually didn't realize that fact until Moe pointed it out.
- Take That!: At the end of the episode, during the James Bond theme song, a list of canceled shows scrolls by that the Simpsons has outlasted, including Allen Gregory, The Critic, Futurama, and the Untitled Seth MacFarlane Show 2017 (which turned out to be The Orvillenote ).
- Taking the Bullet: Played for Laughs in "BFF R.I.P." when Snowball II takes Rachel's knife, meant for Marge, and falls dead into the trash- just in time for Homer to take it out.
- To Be Continued... Right Now: During "Dry Hard", there are four title cards for "End of Part 1", "Part 2", "Part 3", and "Part 4".
- Villain Ball: Sideshow Bob and his "Furious Four" have the Simpsons at literal machete-point before going into a Irish victory jig, immediately after which Maggie wakes up and goes Off with His Head! on all of them.
- What Happened to the Mouse?: After Bart frees Lisa from jail in BFF R.I.P. he disappears from the rest of the story and isn't shown in Rachel's list. It can be assumed that Bart was just removed from the story due to time constraints, or, Rachel didn't put him on the list because she still considered Bart as someone Lisa hated.
- Yandere: Rachel wants to kill all of Lisa's best friends, so that she can be the only one left!
