🚨 There are MASSIVE — and I mean MASSIVE — spoilers ahead for Stranger Things Season 4! 🚨
1. First, the Hellfire Club is most likely a reference to the Hellfire Club from the X-Men comics. In the Marvel comics, this club is notably made up of bad guys, who take Jean Grey and try to use her and her powers as a weapon, which is similar to what Eleven goes through during Stranger Things.
2. Also, way back in Season 1, Will wins Dustin's X-Men Issue #134 from 1963 after winning their bike race, and that issue follows the X-Men as they go up against the Hellfire Club.
3. Lucas's #8 basketball jersey is a nod to Kobe Bryant's first jersey number when he played for the Los Angeles Lakers. Caleb McLaughlin, who is a huge Kobe fan, had the idea to pay tribute to the basketball legend in this way. Kobe's original jersey number was #8 before he switched to #24 during the 2006–07 season.
4. The mullet haircut Mike rocks during Season 4 is actually a nod to Eddie Munson. Mike's long locks are meant to show that he's trying to look like his new role model Eddie. Mike looking up to Eddie also relates to the fact that Mike led D&D campaigns for his friends just like Eddie does in the Hellfire Club.
5. When Eleven and Will go to school with their class projects, you can see that Will did his on Alan Turing, a code-breaker during World War II. This is also a notable Easter egg because Alan Turing was notably prosecuted for being gay, and there have been fan theories suggesting Will is too.
6. Meanwhile, Eleven's project featuring Hopper and the cabin they used to live in is made using an old Reebok shoe box, which is a clever nod to the fact that Joyce always wears Reeboks.
7. When Steve and Robin are driving, Steve mentions that Robin's crush Vicki returned a copy of Fast Times at Ridgemont High paused at 53 minutes and five seconds. Well, that time stamp is when Linda removes her bikini top during a dream sequence.
8. In Jonathan's room in California, you can see that he has a poster for Sam Raimi's The Evil Dead on his wall. The Evil Dead was first released in 1981, with the second film in the iconic horror series coming out in 1987.
9. When Dustin calls Steve from the phone booth at school, you can see that someone wrote "E.T. phone home," which is a nod to Steven Spielberg's E.T. the Extra-Terrestrial from 1982. Spielberg's films have had a big influence on Stranger Things too.
10. While playing Dungeons and Dragons, Dustin tells Eddie, "Never tell me the odds," which is a reference to Han Solo's line in Star Wars: The Empire Strikes Back, which came out in 1980.
11. When Max is recounting the night that Chrissy died to Dustin, you can see that Max was watching an episode of Misfits of Science starring Courteney Cox. The series premiered in 1985 and only lasted a single season, with Courteney playing a telekinetic teenager, similar to Eleven on Stranger Things.
12. In the front window of Family Video, where Robin and Steve work, you can spot a poster for Weird Science, which was originally released in theaters in 1985.
13. And, as Robin and Steve move through the video store, you can also see ads for The Man With One Red Shoe (1985), National Lampoon's European Vacation (1985), Raider's of the Lost Ark (1981), Gremlins (1984), Pete's Dragon (1977) and more.
14. When Angela and her friends torture Eleven at the roller rink, you'll notice that the video recording says that it's March 22, 1986. Now, unless this is a massive continuity error, it's also Will's birthday. This could be why he's so mad that Mike isn't paying attention to him because literally everyone seemingly forgot his birthday.
15. Also, Angela and her friends humiliating Eleven in front of everyone is likely a nod to Carrie (1976), where Carrie, who is also a telekinetic teenager, gets pig blood dumped on her at prom.
16. After the roller rink incident, Jonathan suggests that maybe they go to the movies and see Police Academy 3. In real life, the film hit theaters on March 21, 1986, which is when the first episode of Season 4 is set.
17. When Dustin is telling Eddie some bad news about how the police are still looking for him, he mentions "Cerebro," which is a nod to the X-Men comics. Cerebro is notably the name of a device Charles Xavier uses to enhance his powers in order to find mutants.
18. When Mike goes upstairs to deliver Eleven her Eggo waffles, you'll notice that Eleven keeps her bedroom door cracked open a few inches, which is a nod to Hopper's letter to Eleven from the Season 3 finale.
19. Before the police come for Eleven, you can see that Will and Jonathan are watching an episode of Ewoks in the living room. Ewoks ran for two seasons starting in 1985 and followed the Ewoks that were introduced in Star Wars: Return of the Jedi.
20. When Max is looking through the student files in the guidance counselor's office, you can see the names "John Bonaccorse" and "Ray Brown" before Max gets to Chrissy's file. John and Ray actually work on Stranger Things. John is a second assistant director, while Ray is a key grip. They've both worked on the show since Season 2.
21. The Tom Cruise poster that Nancy has hanging in her room has been there since Season 1. The photo of Tom Cruise was taken in 1980, which is before his first movie roles in Taps and The Outsiders were released in 1981.
22. Also, when Robin is in Nancy's room for the first time, she also looks at Nancy's ballerina jewelry box, which is the same thing Eleven did in Season 1 when she was exploring the Wheelers' house.
23. When Robin and Nancy travel to Pennhurst Mental Hospital to chat with Victor Creel, the hospital was previously mentioned way back in Season 1 when Mike, Dustin, and Lucas first find Eleven after Will's disappearance. Also, Pennhurst was a real mental hospital, and it's believed to be haunted.
24. When Nancy and Robin are shown "The Listening Room" at Pennhurst, you can spot the names of songs on the chalkboard. All of the songs deal with dreams, which links to Vecna and the ongoing theme of nightmares and the fact that songs save people from Vecna.
25. When Nancy and Robin are inside Pennhurst and walk down the hallway to Victor Creel's cell, it's a nod to the moment from The Silence of the Lambs when Clarice visits Hannibal Lecter for the first time.
26. When Victor Creel is in his cell and scratching his fingernails on a desk, it is a purposeful nod to Freddy Krueger, who Robert Englund notably portrayed. It was meant to represent Freddy's razor-sharp blades attached to his fingers.
27. When Jonathan tells Will and Mike about his plan to leave their house and go to Hawkins, he refers to the two officers watching them as "Ponch and Jon," which is a nod to Officer Jonathan Andrew Baker and Officer Francis "Ponch" Poncherello from the popular TV series CHiPs. The series ran from 1977 to 1983.
28. If you look closely, Will has several amazing posters hanging in his room, including one for R.E.M, Jaws, and the musical Little Shop of Horrors.
29. When Max is reading the letter she wrote for Billy, you can see that Max's handwriting is a script-print mix. Sadie Sink explained that she actually wrote the letter and her usual handwriting is cursive. However, the production team thought that Max would most likely write in a print-like font, so Sadie created a "hybrid," which is a perfect mix of her own handwriting and what she thought Max's would look like.
30. When Max is brought into Vecna's world during "Dear Billy," you can spot what appears to be a Myers gravestone, which would be a nod to Judith Myers' gravestone from Halloween (1978), and Max notably dressed up as Michael Myers for Halloween in Season 2.
31. Max escaping Vecna thanks to "Running Up That Hill" by Kate Bush isn't the first time music has been used to defeat creatures from the Upside Down. In Season 2, Jonathan notably played Will's favorite song "Should I Stay or Should I Go" by The Clash while he was possessed by The Mind Flayer.
32. When Nancy, Robin, Steve, Dustin, Lucas, and Max enter Victor Creel's house and Dustin reveals he has flashlights in his backpack, you can spot a Ghostbusters pin. This is a reference to Dustin, Lucas, Mike, and Will dressing up as the Ghostbusters for Halloween in Season 2.
33. When Mike, Jonathan, and Will call the number for the Nina Project, Will mentions that the sound of the computer reminds him of WarGames. Then, Mike even wonders if Nina is like Joshua, who is the computer in the movie. WarGames came out in 1983 and follows David, who accidentally hacks into a US military supercomputer.
34. When Lucas and Max are exploring Victor Creel's old house, Lucas makes a joke about if he plays the piano correctly, a secret door might open. This is most likely a reference to The Goonies (1985) where Andy has to play a piano perfectly in order for the crew to find One-Eyed Willy's treasure. Goonies is yet another Steven Spielberg film referenced in Stranger Things.
35. When Eleven is recreating the crushing Coca-Cola moment from Season 1, you'll notice that she's crushing a "classic" Coke can. In 1985, Coca-Cola tried a New Coke formula and then changed it back to the "Classic" Coke formula. New Coke was mentioned throughout Season 3 of Stranger Things as well.
36. Throughout Stranger Things Season 4, there are a lot of similarities to the movie Labyrinth (1986), including the use of clocks, and Steve and Robin even mention a Muppets joke in Episode 2.
37. And finally, when 001 becomes Vecna, the music playing in the background is the same as when Jon Osterman becomes Dr. Manhattan in the Watchmen film. In Watchmen comics, Jon is put into a particle accelerator, is ripped apart, and then becomes an all-powerful being, which is similar to Vecna.
