Lisa uses an app from iRunes, a parody of iTunes, to translate the message on the desk.
There is a demon boy being punished by writing on the chalkboard like Bart does in the opening gag.
Two bullies shove a student into a locker that's modeled after the Iron Maiden torture device.
One of the kids is punished on a doughnut feeding machine that was used to punish Homer in Treehouse of Horror IV.
Hot Stuff makes a short appearance. He was placed in "super hell" for how "lame" his comics are.
Pat Benatar's song "Hell is for Children" plays in the background of the first segment, while Bart is showcasing his lessons.
Bart after having his skin removed in Hell class is a reference to his inside-out form from the end of Treehouse of Horror V.
Bart's classes parody the following lessons:
Long Division; instead of algorithms, Bart stretches and bifurcates a Satyr with an axe.
Show and Hell from Show and Tell.
Keeping the Yankees in First Place.
Quantum Satanics from Quantum Mechanics.
The books Bart receives for his The Literature of Hell class, parody the following:
Tender Are My Whipped Buttocks from Tender is the Night by F. Scott Fitzgerald.
Fahrenheit 451,000 from Fahrenheit 451 by Ray Bradbury.
I'm Not Even Dead Yet by John Irving. At the time of this episode, John Irving is still alive, since the previous authors have already passed away.
The O'Reilly Factor for Kids by Bill O'Reilly, an actual book and the only one that's not a parody.
Marge's bumper sticker states "My child is an honor student in Hell" with a satanic star as a symbol.
Instead of no. 2 pencils, the teacher writes no. 2 pitchforks on the chalkboard during Bart's final exams.
The Executive Producer's title in this episode is cat westbrook /dev/null, which is a reference to a Linux shell command, and also a reference to Jeff Westbrook's Computer science researcher profession.
Bart's full name in Hell is Beelzebart, a pun of the name Beelzebub, which is another contemporary name for the devil and the name of the patron demon of gluttony from the seven deadly sins.
Bart got straight A's, just like "Lisa got straight A's..." (Marge wrote this in the letter to the friends of the Simpson family), a quote from the Simpsons Christmas Special that was aired 25 years ago.
The portal Bart and Lisa use to get back to earth leads them to Mr Burns' office.
The scene where Moe is bashed with a statue in a raid on his home is a reference to a scene in "A Clockwork Orange" where Alex raided the home of a wealthy cat lady who is killed by Alex with the cat lady's statue.
This segment has the same name and is based on The Others.
The channel that the TV is on when Homer first changes the channel is FXXXXXX, a parody of FXX. FXX was launched as a TV channel in 2013 as a sister network to FX, replacing Fox Soccer. FXX picked up rights to air The Simpsons in November 2013 and aired a 12-day marathon of the show, airing all episodes from seasons 1-25 (552 in total) from late August to early September of 2014. Since the marathon, FXX has aired the show on a regular basis.
During the initial haunting of the Simpson residence, the television loops the former Fox sitcom "Married... with Children" throughout various channels, such as The History Channel, Al Jazeera, BET, Animal Planet and Syfy. Few of them replace original actors with the ones that their channel focuses on:
Al Jazeera - replaces American actors with Arab actors.
BET - replaces white American actors with African-American actors.
Animal Planet - replaces actors with anthropomorphic animals.
One of the scenes also repeats the short Family Portrait adding today's Simpsons. 1987 Bart tells his father to use a digital camera.
1987 Homer prepares to appear nice in the photo while 2014 Homer is busy drinking a beer.
1987 Marge looks really impatient while 2014 Marge looks nice.
1987 Bart and 2014 Bart start making faces.
1987 Lisa gets bored and starts reading Sweet Valley High, 2014 Lisa also looks bored but starts reading Fifty Shades of Grade School.
Both Maggies look normal.
When the photo is taken, 1987 Homer is strangling 1987 Bart, 1987 Lisa, 1987 Maggie, and 2014 Maggie are making faces, 1987 Marge strangles 2014 Marge with her own red pearls, 2014 Bart is also making faces, 2014 Homer just notices what's happening and doesn't react in time and 2014 Lisa is still reading her book.
In this segment, it is unknown how or who killed Maggie. Some theories are that Maggie was killed by Groundskeeper Willie, or that she got asphyxiated by the oven's gas that Marge turned on.
Although they did have a voice role, this is the first Halloween special where Kang and Kodos do not make a physical appearance. They do actually appear in Season 26 due to their appearances in "Simpsorama" and "The Man Who Came to Be Dinner".
When the Pixar family of the Simpsons enter the house, CGI Homer is voiced by John Ratzenberger from many Pixar films.
This is the second episode of the series where Homer is voiced by two people, the first time that happened was in "Homer's Barbershop Quartet", which this episode was released 21 years ago in 2014 before this episode came out.
In the first segment, Lisa didn't read the ancient text translation (Bart took her tablet before she could read it), but she was taken to Hell with Bart.
In the third segment, just before the camera cuts to the current Simpsons and the Tracey Ullman Simpsons eating in the kitchen, the pink sedan is seen parked on the driveway. Later, when the camera pans across the other forms of the Simpsons arriving at the house, the pink sedan is missing.
Near the middle of the third segment, it shows that 1987 Homer couldn't choke 1987 Bart, yet at the end when the whole family was taking a photo, 1987 Homer was seen choking 1987 Bart.