The Doctor Who episode "Bad Wolf" namechecks Lucifer, from the Doctor Who New Adventures novel Lucifer Rising by Andy Lane and Jim Mortimore. And in "Doomsday" he mentions Arcadia, from the New Adventures novel Deceit by Peter Darvill-Evans (however, "The Day of the Doctor" establishes there's a different Arcadia on Gallifrey).
In Remembrance of the Daleks, the Dalek Emperor disguise used by Davros is based on the Emperor that appeared in the Dalek Chronicles comic, rather than the Dalek Emperor that had appeared earlier in the series.
The new series episode "Dalek" was based on elements of the Big Finish Doctor Who audio drama "Jubilee", and was originally intended to include a pizza box labelled "Jubilee Pizza". This name eventually appeared in a few episodes of Torchwood.
The two-part story "Rise of the Cybermen"/"The Age of Steel" contained an obscure reference to "Paula Moore", the pseudonymous creator of the story Attack of the Cybermen.
The term "rel" as a Dalek unit of time was first used in the very out-of-CanonPeter Cushing movies. It then appeared on and off in various Expanded Universe media before finally becoming "official" in the episode "Doomsday".
Two of the show's original creators were Sydney Newman and Verity Lambert. At one point, the Doctor (well, a memory-modified version of him) says his parents' names were Sydney and Verity.
If you listen carefully, one of the vendors in "The Long Game" is selling "kronkburgers", from the Doctor Who Magazine comic strip "The Iron Legion".
The Torchwood episode "Reset" had the Doctor's former companion, Martha Jones, adopt the pseudonym Samantha ("Sam") Jones, which referenced the character of the same name from the BBC Books Eighth Doctor Adventures. How many got that one?
Also, in episode 19 of Dino Thunder, the main cast spend the entire episode watching a poorly dubbed episode of its source material, Bakuryuu Sentai Abaranger! Presented as a Japanese TV show based on the real-life Power Rangers. (It's episode 10 of Abaranger, for the record.) Best mythology gag ever!
The Cylon designs from the original series are portrayed as outdated Cylon technology from the First Cylon War. Razor even shows original series Cylons in action, complete with monotone synthesized voices and the Catch Phrase "By your command."
Taken to the extreme, in the series finale episode, the old and new centurions engage in hand-to-hand combat on the Cylon Colony.
At the end of the miniseries, as a group of the humanoid models conclude a debate, one gives an order and another responds "by your command."
The original series theme song is re-purposed as the Colonial national anthem.
Several ships in the civilian fleet, most notably the mining vessels and botanical cruisers, are in fact ships carried over from the original series. The botanical cruiser in the remake of Galactica is not a carryover from the original show which of course used footage from the film "silent Running". However the Colonial Movers (with a great slogan 'We Move Anywhere') are.
The design of the Battlestar Pegasus is reminiscent of the original Battlestar Galactica.
Early in the mini-series, an original series Viper is seen in a museum. Since the original Viper used lasers, something not present in the new series, this is most likely a Mythology Gag.
And of course the Peter Pan-derived slogan "All this has happened before, All this will happen again" sounds very much like a nod to the remake nature of the series.
In a recent episode, the opening narration music, from which the Cylon Leitmotif in the original series is derived, appears as the Second Movement of Numian's 3rd Sonata. In the same episode, the Unusual Euphemism "felgercarb" is the name of a brand of toothpaste. Felgercarb, incidentally, meant "shit/bullshit" in the original series...
Don't forget, it's Tauron toothpaste. Taurus means "bull"...
And then there's Tom Zarek, persistent thorn in the sides of Adama and Roslin, who is played by Richard Hatch, the original Apollo.
In the MST3K episode "Soultaker", Joel returns to the SOL, and Mike gets jealous of him after learning Joel manages a hot fish shop. Servo tells him, "Don't compare yourself, Mike, it ain't healthy!" This was a reference to the internet 'Joel vs. Mike' Flame War, from shortly after Mike took over as host after Joel left.
In the final episode, the SOL crash-lands on Earth, and some time later, Crow and Servo are living with Mike at his apartment. The three of them settle down to watch the movie The Crawling Eye on TV, and Crow remarks, "This movie looks kind of familiar, doesn't it?" The Crawling Eye was the movie featured in the first episode of MST3K after its stint on KTMA-TV in Minnesota.
In the Battlefield EarthRiffTrax, Bill Corbett (Crow), upon seeing the title cards, scoffed, "3000? What has the year 3000 ever done for us?"
In the Rifftrax for the first X-Men film Bill wonders why the screen title "The not-too-distant future" sounds so familiar.
Joel(in an undertone): You're not supposed to know about that!
Tom Servo: Oh, right. Sorry.
A very elegant Mythology Gag was done in the BBC's Macbeth episode of their ShakespeaReTold [sic] series. Macbeth (a head chef at a famous restaurant in this version) gives a passionate speech about food, to which one of his underlings remarks, 'That's a bit Gordon Ramsay'. In the hushed silence that follows, another chef tells the poor underling, "We don't mention that name in this kitchen. It's bad luck. Just call him The Scottish Chef." (This, of course, is a reference to the thespian legend that using the title Macbeth in reference to any actual production is bad luck, and so it is referred to as "The Scottish Play" instead.)
The title character's real first name is "Steven", an homage to Steven Holland, who played Flash in the 1954 TV series.
The Dactyls, a tribe of bird-worshipping nomads who wear prosthetic claws and glide on air currents with special capes, are jokingly referred to as "Hawkmen" by a skeptical Joe Wiley.
Ming, now a preening European-style fascist rather than the Yellow Peril despot of the comics, mentions how the people of the Cantons say he's "Merciless". Of course, he proves them right when he strangles a puppeteer with his own marionettes so Aura wouldn't associate with him.
The very same episode, which revolves around a Mongo holiday dedicated to ancestor worship, sees Ming eschew his western-style military uniform for an elaborate robe similar to the one he wears in most adaptations.
When Terek tries to persuade Flash to help him overthrow his father, he tells Flash he just might "save every one of us" — a lyric from the theme song to the 1980 film.
Just about every episode of the 1990 series The Flash contains at least one Mythology Gag referencing one of the several incarnations of the comic book hero. Some include:
Mentions of several Silver Age Flash villains (Professor Zoom, Gorilla Grodd; neither actually appeared in the series, however).
A "Garrick Avenue" address (Jay Garrick was the alter ego of the Golden Age Flash).
While the series is ostensibly based on the adventures of the Silver Age Flash (Barry Allen), in one episode a villain creates a statue of the Flash which wears a winged helmet and winged boots, which were hallmarks of the uniform of the Golden Age Flash.
A mention of "Police captain Julius Schwartz" (Julius Schwartz was a legendary DC Comics editor and a co-creator of the Silver Age Flash).
A reference to "the Hotel Infantino" (Carmine Infantino was another co-creator of the Silver Age Flash).
The appearance of a TV reporter named "Linda Park" (in the comics, Linda Park is the girlfriend — later wife — of Wally West, the modern Flash, and was originally a TV reporter).
A mention of "the intersection of Gardner and Fox" (Gardner Fox was the creator of the Silver Age Flash).
In The Pilot, Barry Allen's older brother was named Jay, another reference to Jay Garrick.
Numerous line echoes, including "And Toto, too" and "Lions, tigers and bears, oh my".
DG's waitress uniform is all but identical to Judy Garland's costume.
Sheriff Elmer Gulch, who wants to arrest DG, references Margaret Hamilton as Elmyra Gulch, who wanted Dorothy arrested and Toto put to sleep.
DG's house number is 39, the year in which The Wizard of Oz was released.
When running across the meadow to the entrance to the Realm of the Abandoned, Glitch stumbles in a manner similar to Ray Bolger's rubber-legged Scarecrow.
Glitch, the Scarecrow analogue, claiming to have been a great dancer is likely an allusion to the fact that Ray Bolger (the 1939 Scarecrow) was a trained dancer.
A dangerous region of the O.Z. in which our heroes find themselves is the "Fields of the Papé", an obvious allusion to the field of poppies.
Briefly tricked into believing her adventures were All Just a Dream, DG claims to have had a dream "in technicolor", referencing the film's transition to color in Oz.
Likewise, when DG goes to "The Gray Gale," and meets an apparition of the original Dorothy Gale, the scene is monochromatic. Just to remind us that the film and the book are two distinct things, Dorothy's slippers are plainly silver.
Using the ruby slippers from the 1939 movie would require paying for a license.
And speaking of Dorothy Gale, she's described as "the first slipper", which, in-story, refers to her being the first to "slip" from our world to the Outer Zone, and metafictionally alludes to the Silver (or Ruby) Slippers.
Also the fact that the Queen (and by extension, DG and Az) are descendants of Dorothy Gale. In the book universe, Dorothy ended up moving to Oz full-time, and was appointed Princess of Oz and Ozma's heir.
The Mystic Man's brief appearance as a giant head floating in the air, heralded by gouts of flame, echoes the Wizard's pre-"curtain" appearance.
The Queen calling out for DG in Azkedelia's viewing tank echoes the image of Aunt Em in the Wicked Witch's crystal ball, and uses some of the same dialogue.
Raw and DG being captured by the Witch while Cain and Glitch are left for dead is a nod to the book. In the original book, Nick and Scarecrow were tossed in a ravine to rot and rust.
The strategem Cain and Glitch use to enter Azkedelia's tower to rescue DG and Raw is the same as that used by the Tin Woodsman, the Scarecrow and the Cowardly Lion to get into the Witch's castle.
Also, a quick way to make this a really fun movie is to play a Drinking Game where you drink every time someone tells Cain to "Have a heart".
There appears to be a reference to Book Oz. The doll DG is playing with appears to look like Princess Ozma.
An extremely subtle one: In Baum's books, the only two members of the original party to have first and last names are Dorothy Gale and Nick Chopper (the Tin Woodsman). Much later, Ruth Thompson gave a name to the Scarecrow. The only two to have a first and last name in the remake? DG (Dorothy Gale II) and Wyatt Cain. Later, Glitch's true name (Ambrose) was revealed in flashback.
Camelot's court genealogist is Geoffrey of Monmouth. In reality, Monmouth wrote History of British Kings, one of the earliest Arthurian sources.
Similarly, at the very end of the musical Camelot (and the book The Once and Future King on which is it based), Arthur knights a young page named "Tom" and then charges him to escape the final battle and live to tell the tell the story of Arthur's reign; "Tom" is clearly supposed to be Sir Thomas Malory, who wrote the definitive volume of Arthurian myth, Le Morte d'Arthur.
The dragon living under the castle is most likely a nod to the story of Vortigern's castle, which couldn't be built because there were two dragons fighting in a cave beneath it.
In early episodes Guinevere sarcastically mutters: "Who would want to marry Arthur?" and - when invited by Merlin to play a game of Who Would You Rather: Arthur or Lancelot - she just laughs and tells him that she'll never have to choose.
Colonel O'Neill of Stargate SG-1 would like to remind you that his name has two "L"s. There's a Col. Jack O'Neil (one "L") who really has no sense of humor! This is a reference to the change in the spelling of his name and in his personality between the original movie and the series.
In addition to the Reference Overdosed nature of the show, Psych is also a fan of this trope, with things like Shawn professing his love to Curt Smith (which is actually James Roday's love).
One episode revolved around a terminator attempting to assassinate the governor of California. In real life, of course, that job is filled by Arnold Schwarzenegger, the original star of the franchise.
Another episode reveals that one of the terminators had taken the identity of an actor, and showed clips of him in a low- budget fantasy movie. His costume is clearly that of Conan The Barbarian, one of Arnie's other roles.
In the second season episode of The Man From Uncle titled "The Bat Cave Affair", Napoleon Solo is escorting the episode's innocent to Europe as they investigate some developments in the plot. A scene on the airliner cuts in just as the inflight movie is ending, revealing a The End card which shows that the inflight movie was One Spy Too Many—which is in fact one of The Man From Unclecompilation movies (basically, One Spy Too Many was composed of the two parts of the second season opening episode, "Alexander the Greater Affair (Parts I and II)" plus added footage).
Clemency McGill: That was a right fine movie. Do you like spy movies, Mr. Solo? Napoleon? Napoleon Solo: I'll tell you, they're alright if you like light entertainment. I just think they're... pretty far-fetched.
And in the third season episode "The Hula Doll Affair", Napoleon Solo receives a message to go to 555 Felton Avenue (which turns out to be the location of THRUSH's New York headquarters). Norman Felton was one of the creators of the series, and credited as executive producer that season.
In one episode of the 1966 TV adaptation of The Green Hornet, a couple of hoodlums pass the time watching an episode of the 1960s Batman TV series on a television in their hideout. William Dozier produced both series.
But... in an episode of Batman, the Green Hornet and Kato teamed up with the Caped Crusader! How doesthatwork?
Then in another episode of Batman, Bruce and Dick turn on the TV specifically to catch the Green Hornet TV show.
In an episode of Buck Rogers in the 25th Century, Buck and a team of older has-been vets including one played by Buster Crabbe (who portrayed Buck Rogers in the early serials) are taking on the enemy space fighters. Buck barks out orders, to which the character played by Crabbe says "I was doing this before you were born." Gil Gerard, the actor playing Buck in the series, answers with a chuckle "You think so, eh?" (After all, in character he was born over 500 years ago) To which Crabbe responds "Young man, I know so."
The Supernatural episode "Hollywood Babylon" takes place on a film set, and contains several references to the shows own production, including the execs' skepticism about salt as a way to battle ghosts, the precision of the lore, and the quality of the catering on set (the cast of the film comment how much it's improved). The producer is even named as McG.
On a further note, guess which day of the week the real-life Castiel is supposed to represent.
In a recent episode, Dean came up with this line after an unpleasant incident: "Must be Thursday."
The sixth season episode "The French Mistake" is nothing but this.
Much like Tin Man, references to the original in The Prisoner (2009) could make for an incapacitating drinking game. In the first episode alone:
93 wears the same outfit Number 6 wore in the original series. (Word of God is the role was originally offered to original Prisoner series co-creator and star Patrick McGoohan, who died soon after.)
6's house is appointed with furniture of the same Zeerust-futuristic style used in the original series.
The scene transition to the inside of 93's house takes us to an extreme close-up of a lava lamp, which reproduces the original series's visual effect for Rover's launch sequence.
A rough sketch of a landmark 93 half-remembered from his life outside the Village is of Big Ben. One of the best-known episodes of the original series was "The Chimes of Big Ben", in which the landmark played a key part in the climax
93 himself bears a striking resemblance to the older version of Number 6 from the graphic novel follow-up "Shattered Village"
During his first meeting with 2, 6 pounds on in the desk between them in a way that seems very unnatural for the actor involved. He's recreating an iconic image from the opening sequence of the original series.
A pennyfarthing bicycle, which was the icon of the original series, is briefly visible during a nightclub sequence.
Clark almost always wears red and blue, the main colors of the Superman costume.
Which may end up not being a gag. Clark has been seen rescuing people at super-speed, and because he always wears those colors they see a red-and-blue blur. In one episode Green Arrow dresses in a costume of those colors to hide his identity. In other words, the series implies his Superman costume will be red and blue because he wears those colors in his civilian life.
At this point, it's safe to say they must be his favorite colors. Fortunately, he's stopped wearing blue and red when he's Clark Kenting.
Superman's iconic S-emblem appears to be the fusion of Smallville High's school crest, a Kryptonian symbol meaning "air" (a shield with an 8 inside it), and a crest on a suit of armor worn by Alexander the Great (pointed out by Lex near the start of the series).
The first line uttered by (teenage) Lana Lang is her reaction to reading "Beyond Good and Evil" — she asks Clark whether he considers himself "man or superman".
The Phantom Zone is now a land of barren wastes instead of ghostlike limbo, as a nod to the Supergirl movie. The scene in which Clark enters the Zone uses a spinning, flying square glasslike panel similar to the one in Superman and Superman II.
The Fortress of Solitude in Smallville is identical to the crystalline design from The Movie.
Before that, Clark's hideout in the barn loft was referred to as his Fortress of Solitude.
In one of their more obscure references: "The Torch" was the name of Jerry Siegel's high school newspaper. Siegel, of course, was one of Superman's two creators. (Ironically, Siegel's heirs are currently involved in a long-running lawsuit over the rights to Superboy that encompasses the intellectual properties — and profits — from Smallville.)
Bart Allen, in the episode "Run", has fake IDs in the names of "Barry Allen", "Jay Garrick", and "Wally West", all Flashes in the comics. Similarly in "Odyssey", Ollie Queen uses the name Roy Conner — Roy Harper was Green Arrow's sidekick in the comics, and Conner Hawke was his son and successor. Bart also wears a red hoodie with the famous Flash emblem on it.
In the episode where Clark is reprogrammed as "Kal-El", he flies to intercept Lex's plane. The pilots notice him on the radar and one says, "What is that? A Bird? A Plane?"
The episode that Pete learns of Clark's superpowers, he comments, "It's not easy to be you." It's pretty safe to assume that this is a direct transfer of the line "And it's not easy to be me," from Five for Fighting's song "Superman."
Which is also likely a reference to the original intent to have that as the show's theme, before they decided it was too soft and went with Remy Zero's Save Me.
The episode "Kandor" features two good ones. First, Chloe remarks that Clark's had feelings for Lois "since 1939" (the year Superman debuted in Action Comics). Second, people actually kneel before Zod.
In Season 9, people kneeling before Zod, or variants of the phrase, could be the basis for a Drinking Game.
A subtle one in "Salvation": Chloe is surprised to learn the League has "our own satellite" ... meaning a dedicated communications sat, not the satellite headquarters from the comics.
The Wonder Twins appeared in "Idol", with cellphones that had a familiarimage◊.
Blackadder Goes Forth: The 'S' in Pvt. S. Baldrick is a Call Back to Sod-off, the first name of the Regency Baldrick. He also worked on a Turnip Street factory. The Baldricks of series two and three were obsessed with turnips.
An episode of the original Law & Order features a perp from a season one episode becoming a murder victim 15 years later. The current detectives even talk to Captain Cragen, who was Captain during that time and has since moved on to the Special Victims Unit.
In Star Trek: Voyager's premiere, Janeway mentions how they are going to "seek out new life and new civilisations." Soundfamiliar? Yeah, the show thought so too — you can hear the original series' Instrumental Theme Tune piping away in the background immediately after she says it.
The Star Trek: Deep Space Nine episode "Far Beyond the Stars". Full stop. The entire thing is one long mythology gag for the entire Star Trek franchise, except that it isn't a humorous episode — all the humor is meta, while the plot is serious.
There's Mythology Gag in to the original series in the episode "Legacy". In the beginning, Picard mentions Enterprise is passing the planet Camus II. Camus II was a planet visited by Kirk's Enterprise in the 79th and final episode of the original series, "The Turnabout Intruder." "Legacy" was episode #80 of The Next Generation, the point at which its run surpassed its predecessor's. Furthermore, the last Federation starship to visit the failed Turkana IV colony was the USS Potemkin. An earlier Potemkin was mentioned in "The Turnabout Intruder."
In the series finale, "All Good Things...", not only do they superbly recreate the look of the first season, right down to the TOS-style miniskirt uniforms worn by some women (although not, as shown in "Encounter at Farpoint", men), but the name of the shuttle used by Picard and Yar on their first approach to Enterprise in the past? Galileo, which was the most famous of the shuttles on board the original Enterprise, yet never before had been referenced on The Next Generation.
A second season episode of The A-Team had Face (Dirk Benedict) being surprised by a Cylon walking by him on a movie set. The scene was incorporated into the opening credits from season 3 on.
At one point in Nikita, Division actually does some good. Nikita suggests that maybe Michael could take it over and set it straight; Michael suggests Nikita could do it. At the end of the original La Femme Nikita, Nikita takes over Operation, of which Division is a counterpart.
In Lost In Oz, Alex finds the remains of Dorothy's house on the western border, and asks why. In the original Oz books, West and East were switched on the map.
The final intro of Zoom in 2005 resembles the 70s intro more than the other intros.
The live action adaptation of Mei-chan no Shitsuji pulls an interesting one of these, when Shibata Kento is at an amusement park with Mei and Mikuru, and points out a live super hero show at the park, but Mikuru isn't interested. Kento is played by Takeru Sato, better known for playing Ryutaro Nogami of Kamen Rider Den-O. It's also worth noting that the actor playing the male lead is Hiro Mizushima, another Kamen Rider alum, in his case having played Souji Tendou from Kabuto.
When Cersei comes to see Tyrion after he is injured in battle, she says that "they said you had lost your nose, but it's not that bad". In the original A Song of Ice and Fire book series, Tyrion atually lost his nose in that battle.
In "Walk of Punishment", Kayla, one of the prostitutes Tyrion hires for Podrick, is commended for her ability to perform the "Meereenese Knot". This is referring to a difficulty George R. R. Martin had while writing book 5 of A Song of Ice and Fire involving the various characters in or heading to the city of Meereen.
One of Queen Selyse's fetuses-in-a-jar is apparently named "Edric", a nod to minor book character Edric Storm. In the show, his plotline was given to Gendry.
When Jaime is trying to locate Alton Lannister in the family tree, he asks him if his mother is "the fat one", only to correct himself by saying "No, there is only one fat Lannister. If she was your mother, you would know it." The book counterpart to Alton, Cleos Frey, is the son of Genna Lannister, an aunt of Jaime that is notoriously obese.
During the Battle of the Wall, a wildling archer attempts to shoot an arrow to the top of the Wall and doesn't even come close. Then a giant steps up and shoots a ballista-sized arrow from a giant-sized bow, sending a ranger atop the Wall and flying. This is a reference to a passage in the books where wildling archers manage a few hits on the brothers 700 feet up, which GRRM has admitted he didn't realize was physically impossible.
In "The Children" Brienne bites Sandor's ear off, a reference to Sandor's burned-off ear in the books.
In the Red Dwarf episode "Psirens", the SCS Pioneer is commanded by Captain Tau, played by Anita Dobson. Tau was also the name of the female captain of the Dwarf itself in the failed US pilot.
The Dr. Frasier Crane Show debuted on KACL on May 21, 1993, the airdate of the Cheers finale.
The season 11 episode "Caught in the Act" has a gag about Kelsey Grammer having played the character of Frasier Crane for 20 years (first in Cheers, then in Frasier). In the episode Frasier meets his ex-wife, who's had a long career as the children's entertainer "Nanny G":
Nanny G: Frasier, if you knew how bored I am, being "Nanny Gee." How trapped I feel.
Frasier: You have a wonderful career.
Nanny G: But nothing ever changes! Do you have any idea what it's like to play the same character for twenty years?
Frasier's agent, Bebe Glazer, has the same first name as the actress who played Lilith.
Dirk Gently has a newspaper with a story about a horse in an upstairs room, and Dirk's wall-o'-clues has the words "ELECTRIC MONK" clearly visible before he paints over it. An Electric Monk (a machine for believing in things) and its horse, which at one point ended up in an upstairs room, played a substantial role in the original book.
In fact, the wall (at least before he clears it in order to use it for his new case) contains a number of clues relevant to the case in the original book, including the aforementioned bored horse (with an arrow connecting it to a bathroom), salt cellar, greek vase, stuck sofa, Kubla Khan and the fact that Michael Wenton-Weakes has been fired.
A 1991 episode of Sesame Street revealed Gordon's last name to be Robinson, a nod to Matt Robinson, the first actor to portray Gordon.
Tyson begins the series on the same rocky outcrop at Big Sur that Sagan did and repeats the Match Cut with the dandelion seed. Near the end of that episode, he repeats Sagan's famous "star stuff" quote.
The second episode is titled "Some of the Things that Molecules Do", a phrase Sagan used in his conclusion of the second episode of the original. It also reuses the "evolution in 40 seconds" graphic.
In the fourth episode he uses the same analogy of a motorcyclist switching on her headlight to explain lightspeed (and the impossibility of exceeding it).
In "Sisters of the Sun" he refers to the Milky Way as the "backbone of night" (which was the title of one of the 1980 episodes) and repeats the heartening speech about a galaxy rise, a morning filled with 400 billion suns.
The Ultraman franchise absolutely loves this trope, particularly when it comes to series from the mid to late 2000s, with the 40th-anniversary entry Ultraman Mebius probably being the biggest example. Almost every time a monster from a previous series appears, you can expect the episode to include at least one Mythology Gag about something that happened in its debut series.
Familiar lines of dialogue from the movie are repeated in the show, such as time travel not being "an exact science", Jones saying "right on the money" when commenting on the accuracy of the time machine, and Cole's assertion that everyone in the past is "already dead".
In both the film and the show, there is a recording made by Railly which provides important information to the scientists in the future and thus drives the plot.
In both the film, as well as the pilot episode Splinter, Cole infiltrates a dinner party/event thrown by Leland Goines, though for very different reasons.
In the film, Cole is accidentally sent back to WW1 before being sent to 1996. In 1996, Railly finds a photograph of him from WW1, which convinces her that he's a time-traveler. In Mentally Divergent, Cole is accidentally sent to North Korea in 2006, before being sent to 2015. In 2015, Railly finds photographs of Cole from the 2006 incident, including a picture of a note Cole was carrying which allows her to track him in 2015.
In the early part of the film, Cole ends up in a mental institution after being considered insane by local authorities, where he meets fellow inmate, Jeffrey Goines. In Mentally Divergent too, Cole ends up in a mental institution, albeit this time, he deliberately infiltrates it to find fellow inmate Jennifer Goines.
Mentally Divergent itself references a mental patient explaining he's this, and then asking if Cole is as well.
Alternate-universe Luke says in a So Bad, It's Good commercial that Magnus helped him realize the police force wasn't his calling but running an antique bookshop. In the books, Luke is a bookseller rather than an officer.
Alternate-universe Magnus has two cats named Chairman Meow and Church. In the books, Chairman Meow is Magnus's kitten, whose birthday party gets crashed by the main charactersnote Yes, the kitten's birthday party, not Magnus's, and Church is the resident cat at the New York Institute.
In season 11, Tori (played by Alex Steele, the sister of Cassie Steele, who played Manny in seasons 1-9) is subjected to the same "demeaning" mascot job that Manny was by the Alpha Bitch.
After having bromine spilled on her pants, Shay wears gym shorts just like Emma did during season 1 when she had her period in class.
Degrassi has been a training ground for a generation of young Canadian actors who have gone on to bigger things, but one of the biggest is without a doubt Aubrey Graham, better known as Drake. So when the show made a Channel Hop to Netflix and became Degrassi: Next Class, what do they open the show with? Maya quoting "Started from the Bottom". Doubles as a Celebrity Paradox.