The Incredible Hulk #418 featured Marlo selling her soul to Mephisto (she thought it was just a dream) in order to have a perfect wedding day. Over a decade later Spider-Man: One More Day comes out, a story which involves Mephisto convincing Peter Parker to sell his marriage to him.
In Amazing Fantasy #15, the introduction of Spider-Man back in 1962, the wrestler Peter defeats is called Hogan...
When John Byrne redid the origin in the late '80s, he deliberately redesigned Crusher Hogan to look like Hulk Hogan as a result of this.
The Movie referenced this by having Macho Man Randy Savage play the wrestler, who was called Bonesaw. Macho Man and Hogan have a long past.
A 1996 issue of Excalibur has Pete Wisdom, in a wheelchair and a bald cap, humorously pretending to be Professor Xavier, including a reference or two to Jean-Luc Picard while he's at it. Four years later, Patrick Stewart was in fact cast to play Xavier in the X-Men films.
This similarly makes the X-Men/Next Generation crossover comics/novels that much funnier, since many people pause at the resemblance between Xavier and Picard. It's even lampshaded by Storm in the novel.
Even more hilarious, Patrick Stewart related a tale from that comic while on the The Daily Show promoting X2: X-Men United. Apparently, he was told about the comic during its production, as well as the fact that Picard and Xavier would be "facing off" on the cover. Sir Stewart jokingly objected, claiming "If I took that role someday, I'd be on the cover twice. That just doesn't seem fair." It's good to know that Sir Patrick Stewart himself appreciates this trope.
In issue #41 of Generation X, Skin went to rent a bunch of horror movies, the titles of which were parodies of classic horror movies (like Yell! instead of Scream. But among these horror flicks was a film called Sicko, which nowadays makes readers think more of Michael Moore and less of Psycho.
Once, Deadpool claimed, "If you looked like Ryan Reynolds crossed with a shar-pei, you'd understand!" Ryan Reynolds had already outted himself as a Deadpool fan and expressed interest in playing him in a movie at this point, though.
And then he did play a ...version of Deadpool in X-Men Origins: Wolverine, as well as signing on to do an official Deadpool movie.
In the 1990s, Marvel published a few comic books starring Disney characters. They have since been bought by Disney.
In the early days of The Mighty Thor, Thor, in his human guise of Dr. Donald Blake, had a romance with his nurse, Jane Foster. However, he kept the secret of his dual life from her, and Jane, knowing that there was some deep secret that the man she loved refused to tell her, slipped into a crippling depression that took a toll on her physical health. Donald finally snapped her out of it by transforming into Thor at her bedside to prove his love, saving her from "dying of a broken heart". Guess who got to play Jane in the Marvel Cinematic Universe? Natalie Portman.
In Marvel Year In Review 1993, there was a fake ad for Alpha Flight: "We're the Canadian Football League of superhero teams! (Except our best heroes don't go to the U.S. and join the Avengers)". Several years later, Wolverine joined the Avengers.
They also had a bit where they discussed the progression of Darker and Edgier versions of characters, and theoretical Darker-er and Edgier-er extensions. One of them was named Red Hulk. Later on, Red Hulk became a Hulk villain.
Another one with Spider-Man. Peter David wrote that Ned Leeds was the original Hobgoblin. Not only was this questionable, but the original writer of the Hobgoblin mystery, Roger Stern, came back to do a miniseries where it was revealed Leeds wasn't the original Hobgoblin at all. Even if David himself doesn't appreciate the irony, one does have to find it a little funny that the same thing happened to him about the (Green) Goblin mystery in Spider-Man 2099.
You can't really place the blame on Peter David, though, since it was all a massive editorial imbroglio. Not quite as bad as the Clone Saga, but every time the writer or editor on Amazing Spider-Man was changed, the Hobgoblin story got further and further from where Stern had meant it to go.
In Marvel Civil War, shapeshifting alien Hulkling of the Young Avengers replaced Hank Pym to free the anti-registration heroes. This becomes funny when Secret Invasion reveals that the Hank Pym Hulkling replaced was himself a shapeshifting alien that had replaced Hank Pym.
And before that in an issue of Fantastic Four, as a prank, it showed Hank Pym using an image inducer to pose as a car stealing skrull.
This cover of Avengers 221◊ published in 1982 is amusing when you look at the original lineup for Brian Michael Bendis's New Avengers published 23 years later.
Back in Avengers #151, a news report cited Spider-Man, Daredevil, and Namor as three solo heroes who had turned down offers to join the team, closing with "Some people just aren't meant for teams, it seems." All three of those characters have since had high profile stints with the team, with Spider-Man and Daredevil joining in the above-mentioned New Avengers era.
The widely-disliked Hulk cartoon from the 90's had a subplot where Rick Jones became exposed to Gamma Radiation and transformed into a teen Hulk. Marvel eventually introduced a teen Hulk (the above-mentioned Hulking) in Young Avengers, while Rick Jones gained a Gamma-powered alter ego in Jeph Loeb's Hulk run.
This panel◊ becomes funnier after knowing what Captain America does during the Civil War storyline.
This Superman cover is more funny after Spider-Man's breakup with Mary Jane...
Look at the first panel of this◊ Spider-Man comic. Yeah.
An old Marvel Comics Star Wars comic dated about 1980 (before Empire or Jedi came to theaters) had a letter to the editor complaining about how the writers of the comic were writing Luke and Leia out of character saying and I quote "they're obviously in love with each other but you're writing them like they're brother and sister or something."
One issue of the Marvel Star Wars comic, also pre-Empire, had a story about Darth Vader and Luke's father as two different people. Naturally, going off the first movie there was no reason to suspect they weren't two different people, but it's still hard to ignore.
Much of Marvel Star Wars came out between the films. After The Empire Strikes Back, they ran a storyline involving a new Imperial superweapon called the Tarkin. During a briefing, someone says to our heroes, "It answers a lot of questions we've been asking ourselves lately. Like for instance, why hasn't the Empire constructed a second battle station like the Death Star that almost destroyed our base on Yavin?"
Joe Quesada once said the Classic and Ultimate Marvel universes meeting would be a sign that Marvel had "officially run out of ideas." The makers of Spider-Man: Shattered Dimensions didn't get this memo. Well, granted, they don't actually interact with each other, but still.
Issue #58 of the second run of What If?, released in 1994, asked the question of what would have happened if the Punisher had killed Spider-Man. One splash page of the issue shows a montage of big name Marvel superheroes with ties to Spider-Man beating the crap out of the Punisher. This was released only one year before Garth Ennis's The Punisher Kills the Marvel Universe.
The very first issue of What If...? asked "What If Spider-Man had joined the Fantastic Four?"; since then, this has actually happened not once, but twice in 616 continuity - Spidey was a member of the short-lived New Fantastic Four, and later a member of the proper team in place of his dead friend Johnny Storm.
Moreover, What If...? #30's premise was "What If Spider-Man's Clone had not died?", based on a then-recent story arc. Then in the 90s, the idea was revisited in earnest in the infamous The Clone Saga.
Similarly, issue #51 of volume 2 was "What If the Punisher became Captain America?", which later became an actual Punisher: War Journal storyline in 2007. Granted, he was never officially Cap, but this was before Bucky Barnes stepped into the role, meaning he was effectively the closest thing to the real deal out there.
Speaking of Bucky, there's an issue of the first volume ("What If Captain America & Bucky had not disappeared at the end of World War II") where at one point, he takes up the Captain America mantle to replace an aging Steve Rogers. That's right, Bucky was Cap a good 31 years before he takes up the identity in the main Marvel Universe.
An issue of The Invaders from the 70's had a scene where Bucky makes a joke about going through an identity crisis. This was years before readers found out he'd been Brainwashed and transformed into a murderous Soviet assassin.
Not only that, but issue #9 of the second volume asked "What If the New X-Men had died on their very first mission?" X-Men: Deadly Genesis would reveal that this is exactly what actually happened, because Professor X had gathered a new team to save the originals from Krakoa before the more familiar "All-New, All-Different" guys.
Washed-up actor Henry Hellrung, alias Anthem, was made leader of The Order, California's Initiative team, by his friend Tony Stark. Henry was famous for playing Iron Man on television, until alcoholism ruined his career. To recap, he's an actor who got fired because of issues with addiction, then came back into the fore of media attention after accepting an offer to do with Iron Man... not unlike Robert Downey, Jr. The Order ran for 10 issues in 2007; Iron Man came out in May 2008
In a 2005 issue of She-Hulk, Spider-Man had some fun with J. Jonah Jameson by claiming that the real reason Jameson hated him was because he was black. The current Ultimate Spider-Man, introduced in 2011, is Miles Morales, a black Hispanic who was heavily criticized by real life political pundits like Lou Dobbs and Glenn Beck.
An old issue of Thunderbolts had a scene where Hawkeye mentioned that Wolverine was the exact kind of loose cannon who would never be admitted into The Avengers. Guess who joined the Avengers back in 2005 and is still a member of the team to this day?
Another Hawkeye related one; Hawkeye decided to become a hero after watching Iron Man in action and wanted to be a superhero like him. In the mid-late 2000s Iron Man came out, and reportedly, when Jeremy Renner watched it, he wanted to play a superhero, just like Iron Man. He got his wish, how? By playing Hawkeye in The Avengers. Too bad they didn't explore Hawkeye's backstory or explain who he is.
Lampshaded by the official Marvel Tumblr, which called the issue "the first appearance of Loki, and the first appearance of a Loki fangirl."
As the "One Nation Under Doom" event in the Marvel 2099 line drew to a close John Herod used a clone of Captain America as a puppet to overthrow Doom with the cover story that Steve Rogers had once again been put in suspended animation in a block of ice. In Manifest Destiny, we find out the real Steve Rogers's fate and as it turns out, history really did repeat itself.
During the infamous "Armor Wars" storyline in Iron Man, there was an issue where Rhodey dressed up in Whiteface in order to pose as the villain Electro. While removing the makeup, a thoroughly embarrassed Rhodey said he hoped there weren't any black people around to see him like this. This becomes funny when you realize that in The Amazing Spider-Man 2, Electro was Race Lifted into a black man.
Another hilarious moment caused by Electro's Race Lift comes from Mark Waid's Irredeemable, where the character Volt complains about black men with electrical powers being a stereotype. At the time, this was referencing characters like Black Lightning and Static.
During Mark Gruenwald's historic Captain America run, there was a scene where the government was looking up potential candidates to become the new Cap after Steve Rogers retired from the role. The Falcon was briefly brought up as a candidate, but one of the politicians present shot down the idea while saying something to the effect of "The public isn't ready for a black Captain America". When you realize the controversy around the later Truth: Red, White, & Black series (which established there WAS indeed a black Captain America), you can't help but feel that maybe the politician was (sadly) onto something...
From Amazing World of DC Comics, July 1976, describing the Great Disaster at DC Comics:
The pivotal time will be October, 1986 ... and in that month, the future of the world will be decided. Either the path of the Great Disaster will be taken, and civilization will fall, or the path of sanity will prevail and the Legion of Super-Heroes will emerge triumphant a thousand years later.
That's just I Want My Jetpack, right? Well, not quite. 1986 was the turning point for the Dark Age of Comics. And DC comics from October 1986 include Man of Steel #1, which began the modern revamping of Superman, and Batman #400, which was the last pre-revamp Batman. Depending on whether you think the Dark Age was a great disaster, this may be amusingly prophetic....
A 1997 Justice League story had the JLA take on a mad scientist who had created a "luck machine" that altered probability in his favor, letting him win the lottery, the Nobel Prize, and become President of the USA in short order. The JLA confront him in the Oval Office and destroy his device, but when reality reorders itself, the President who thanks the team isn't the right President either, and the team realizes that reality is still broken. What's so funny about this? The "wrong" President looks just like Sarah Palin.
Then-current Adventures of Superman writer Jerry Ordway would often say "Let's just kill 'im!" whenever the Superman writing team are stuck on ideas. When their proposed "Superman marries Lois Lane" story arc was temporarily shelved to avoid conflict with the Lois & Clark: The New Adventures of Superman TV series (which also planned to marry Superman and Lois in a future episode), Ordway, at the next meeting, said, "Let's just kill 'im!" The end result was The Death of Superman.
On the back cover of the Batman: A Death in the Family trade paperback, in which Jason Todd, the then-current Robin, was killed off, then-Batman editor Denny O'Neil jokingly said, "It would take a sleazy stunt to bring (Jason) back", though he did admit that he voted for Jason to live. In 2005, Jason was brought Back from the Dead.
Similar Word of God tripping-up occurs in the afterword to The Return of Barry Allen, a storyline in which Barry Allen does not actually return (yet). Mark Waid hyperbolically describes being driven up a bell tower with a rifle out of sheer exasperation at people asking him to bring back Barry.
"What is it with you people?" I screamed. "Barry is Dead! Gone! Hearsed! Why can't you let him rest honorably, in peace?"
Comic Book Guy: I believe that's the sound the Green Lantern made when Sinestro threw him into a vat of acid. Eepaa!
Sadly, no vats of acid were involved.
The original Batwoman, Kathy Kane, was introduced in the '50s in response to Dr. Frederic Wertham's allegations that Batman and Robin were lovers. The current version of Batwoman, Kate Kane, is a lesbian.
An issue of JLA featured Superman attending the funeral of Metamorpho (again...), and was the only one there. When he questioned the priest about it, he was told that since Superman came back, everyone expected superheroes not to stay dead, so they'd lost interest in memorial services. The service took place in a park dedicated to fallen superheroes, and in an obvious bid to make the point that this wasn't always the case, that sometimes dead heroes stayed dead, the artist had four memorial statues in the scene: Ice, Oliver Queen (Green Arrow), Hal Jordan (Green Lantern) and Barry Allen (the Flash). All of them have since come back from the dead.
This panel◊ from Justice League America #33. At the time, it was meant as a dig at Barbara Gordon's fate in The Killing Joke, but with the events of Countdown to Infinite Crisis (Max actually does shoot Blue Beetle in the head) it becomes hilariously prophetic. (Perhaps justified in that Booster was from the future. Was he trying to subtly warn his friend without disrupting the space-time continuum?)
In the 1970s Batman story "The Man Who Falls", which chronicles young Bruce Wayne's training to become Batman, Bruce meets with an FBI agent who says "we don't pull our piece much. We leave that to Efrem Zimbalist, Junior", in reference to the TV show F.B.I. which starred Zimbalist Jr. Efrem Zimbalist Jr would later be the voice actor for Alfred Pennyworth on Batman: The Animated Series.
Issue 3 of JLA: Year One (written in March 1998) has a moment that seems to be intended as a Funny Aneurysm Moment, due to being set in the past; the Flash (Barry Allen) and Green Lantern (Hal Jordan) have a heart-to-heart conversation about the life expectancies of superheroes, which ends with Hal assuring Barry that "I predict we'll both live to a ripe old age". At that point in continuity, both Hal and Barry were dead. However, these days that moment has reversed into Hilarious in Hindsight due to both having been brought back from the dead throughout the 2000's.
In the "World's Finest" where Robin (Tim Drake) and Superboy (Kon-El) first meet, Superboy wisecracks that even with the costume, he knew it wasn't one of the legendary Flying Graysons. Guess which Robin was made into a contemporary of Superboy in Young Justice cartoon?
Speaking of Tim and costumes, DC once released a book about Bruce Wayne's costume designs for him and his team (Knight Gallery). Tim's section 2 entries stating "yeah, cape-wings are stupid". Cue the New 52 reboot, and just guess what Tim is now wearing (and everyone is making fun of)...
In Messner-Loebs's run on The Flash, there were several references to T. O. Morrow being stricken with depression after seeing something unspecified and horrible in the future. 15-20 years of canon developments and potential things for a reader to dislike later...
Back when Two-Face was still known as Harvey Kent, the editors decided to give him a happy ending, and his face was restored by a doctor. And the doctor's name? Ekhart. In The Dark Knight, Aaron Eckhart would play Harvey Dent.
Some older comics contain fan letters from one Geoffrey Johns, who had suggestions like "What if Superboy's DNA was half Lex Luthor?" and "Could you do another story with [dead at the time] Professor Zoom?" He got responses like "Sorry, in the time since you sent your letter the other half's been revealed as Paul Westfield" and "Sorry, Professor Zoom's dead and we're cutting back on time travel stories." Then he grew up and made his dreams come true.
The second issue of Grant Morrison's Animal Man run has a scene where Buddy runs into a teenager in LA named "Jaime", who collects autographs from famous superheroes. When he opens up his autograph book to try to get Buddy to sign it, the first visible page reads, "To my good friend Jaime - The Blue Beetle". That issue came out about 18 years before a teenager named Jaime Reyes officially became the third Blue Beetle in Infinite Crisis.
In the Deathstroke the Terminator tie-in with the Titans $ellout $pecial, a toy company is producing a Deathstroke action figure set, including "Wintergreen: Friend from Down Under!" When one of the execs points out Wintergreen's British, they're told that Australia is cooler. In Arrow, not only is Wintergreen an Australian, so is Slade himself!
In the MAD parody of the 1966 Batman TV show, the villain who's been trying to kill Batman turns out to be Robin in disguise. Fast-forward 35 years to Frank Miller's The Dark Knight Strikes Again, where the maniac posing as the new Joker, who's been taking out heroes left and right turns out to be...Dick Grayson.
This comic, depicting Superman's face turning various colours from different emotions. Including "yellow from fear".
In the Batman arc "Shaman", Batman ambushes a group of thugs in a drug deal and interrogates the last one, saying "So if you don't tell me every little thing I might want to know, you'll be going to jail in a baggie. Believe it." Anyone who watches anime will know why it's hilarious to have Batman say this.
Image United is a Crisis Crossover designed to celebrate the history of Image Comics. Due to massive Schedule Slip, it's now fallen many months behind. One of the most infamous issues of early Image being its delays.
Judge Dredd's Democracy Now 1990s story line had the quote "When some creep's holding a knife to your throat, who do you want to see riding up...me - or your elected representative? Think about it." Fast forward to 2009 and the elected Mayor of London Boris Johnson saved a woman from a mugging that he witness as he cycled home. Since Mayor Of London comes with no 24 hour bodyguards or police escort it seems elected representatives are a better choice than coppers.
Can be considered an inversion, Dr. Seuss's wartime political cartoon showing a man in the future telling his grandson about his days during WWII, which he apparently spent complaining about fuel shortages. This becomes much less ludicrous when you look at the date this is supposed to be taking place: 1973, when everybody talked about fuel shortages. If you didn't know this was written in 1943, there isn't much of a joke, since it is perfectly reasonable that the grandfather is recounting his past experiences with fuel shortages.
Don Rosa's 2002 Uncle Scrooge story "The Dream of a Lifetime" features the Beagle Boys using an invention stolen from Gyro Gearloose to sneak into Scrooge's dreams and learn the combination to his money bin's main vault. It also features a staggering amount of similarities to the lucid-dreaming mechanics, and some of the plot elements, of Inception.
In 1996 Marvel and DC made a crossover (Elseworlds) Batman & Captain America. No comment about the story itself, however epilogue has a very significant detail. Batman and Robin found frozen Cap, and save him. Then they reveal that Batman is now Dick Grayson former Robin (and Bruce retired now), and Robin is... Bruce Wayne Jr. son of the original Batman! Now where have i heard that one before?
For the Grand Finale of his League of Extraordinary Gentlemen saga, Alan Moore wrote a scene involving a climactic face-off between a deranged Harry Potter and a Guardian AngelMary Poppins...about two or three months before anyone knew that the Opening Ceremony of the London Olympics would feature almost the same thing. Sure, it was Voldemort against a swarm of Mary Poppinses in the latter case, but the coincidence is still pretty astounding. Especially since the book finally hit the stands almost exactly a month before the London Olympics started.
The Star Wars comic compilation Star Wars Tales has a throwaway drawing in one of the stories of the Empire's sigil with Mickey Mouse ears on it. The gag became a lot funnier when Disney bought the rights to Star Wars in late 2012 and announced production of a new series of films.
This article, posted before the comic series was announced, showing fanart of the (humanized) Mane Six as pin-up superheroines, mentioning "Somewhere 'bad girl artist' J. Scott Campbell is smiling". Campbell did do a variant cover◊, with no Fanservice in sight!
In Diablo III, a unique unicorn monster found in Whimsyshire was named "Nightmarity". The name isn't used in the comic, but Rarity becomes the second Nightmare Moon.
In "Explorers On The Moon" (1954) Tintin becomes the first man to walk on the moon. Almost 15 years later man would really walk on the moon surface.
British author Harry Thompson noted in his biography "Tintin and Hergé: a double biography" that in "The Mysterious Star" (1940) mushrooms grow to enormous size before they explode. Five years later, he wrote, the first atomic bomb would explode and produce large mushroom clouds...
Astérix : In "Asterix in Britain" (1966) Asterix, Obelix and their British friend Anticlimax cross the English Channel and arrive while it rains. Obelix remarks that building a tunnel between the French and British coast might be a good idea. Anticlimax answers: "We thought of a tunnel ourselves. We've even started digging one but it seems to be taking a jolly long time, what." When the story was first published in 1966 people had thought of building a tunnel between Great Britain and France for centuries, but it didn't seem likely that this plan would ever come to fruition.
In a Dilbert strip from early 1992, Dogbert announces his intention to run for president, "hoping [his] charisma will unify a divided political party" - not the Democrats, but the Communists, as he wants to have a chance. A few years after Bill Clinton won the election, Scott Adams wrote in a compilation, "This joke made sense in 1992. Trust me."
In a Bloom County Sunday strip, Steve Dallas has a fantasy of dancing around as Michael Jackson. Of course it was cool and badass in 1986...
In the collected volume, Breathed comments "I was off one year. Funny thing looking back is that George apparently did lose his head."
And then there's the strip from 1988 where Frank tells Binkley's dad "The first black in the White House will be a conservative". Well, it kind of depends on how you define "conservative"... a lot of Obama's policies tend to be somewhat in the Nixon range, but he is a Democrat...
Obama's health care law closely copied the one Republicans proposed in 1993, so there's no disputing Obama's conservative bona fides (without resorting to a Chewbacca Defense). However, he campaigned as a progressive liberal, so it's pretty ironic all around.
In the lead-up to the release of The Phantom Menace, Foxtrot had a strip about Jason posting fake news about the movie in order to convince other fans not to see the movie, allowing Jason a better chance to get tickets on opening day. One of the rumors he posted concerned how all CGI effects had been removed from the film, and as such Jar-Jar Binks had been renamed "Jar-Jar Binks, master of invisibility." Considering the eventual fan reaction, Peter's comment about why Jason's plan won't work is made a bit funnier.
Not to mention that the whole strip seems eerily like it could be a parody of notorious Fanon website SuperShadow.com.
Wordof God even acknowledges the unintentional humor in his Best of Foxtrot collection.
In another strip, Jason made a violent video game, but it could also be played in a hyper-sanitized mode to avoid parental backlash. ("Your flower is spurting butterflies from its chest wound.") Then, Serious Sam HD comes, with Super Happy Funtime mode.
In one strip from June 1988, Peter calls a woman on the phone, who thinks he's someone named "Steve", causing Peter to ask who Steve is. Four months later, we meet Peter's best friend, named Steve.
A Pearls Before Swine strip showed Rat writing about a fake interview with Saddam Hussein who was found in a spider hole, playing a Game Boy. As Stephan Pastis wrote in commentary, Saddam Hussein was found in a spider hole, but not playing a Game Boy.
Similarly, one Story Arc involved Osama bin Laden living with the cast of The Family Circus. Later, it turned out that bin Laden was, indeed, hiding in plain sight.
In a strip from an arc where Pig had Newt Gingrich as a pet, Rat said that Newt can never be president and John McCain is a lock for 2008. He was proven right about the former, considering Newt's dropout of the 2012 election, but wrong about the latter, considering the other nominee won that election.
Re-runs of the For Better or for Worse comic strip featuring Lawrence are funnier when you realize that Lawrence is gay. Like when he teases Michael for liking girls, when the boys take turns pulling each others' uvulae (it's that hangy thing in the back of your throat) or when teen Michael tries to comfort a dateless loser friend by pointing out Lawrence doesn't date either.
A Peanuts comic strip had Snoopy try to get Schroeder to recommend him for "Neighborhood Dog Of The Year". Schroeder said that Snoopy never said anything good about Beethoven. Snoopy then thinks that he didn't know Beethoven wanted to be "Neighborhood Dog Of The Year". 20 years later, a film series was made about a dog named Beethoven.
One strip had Snoopy writing something titled "A Sad Story". Lucy calls it dumb, which is a frequent complaint levied against a fanfiction by that same title.
One strip has Linus mention to Charlie Brown that when Sally grows up, there will be three Major Leagues. In 2001, Major League Lacrosse joined Major League Baseball and Major League Soccer as sports leagues under the label, Major League. Let's also not forget the film franchise of the same name.
Linus' comment in context clearly is meant to refer to a third baseball league in addition to the American and National leagues ... this hasn't happened (yet), but the existing ones did add more teams. Very few people in the US cared much about soccer or lacrosse in 2001, and when the strip was originally published, it's not much of an exaggeration to say no one did.
In one Calvin and Hobbes Sunday strip, Calvin is out shopping with his mother and tries on some sunglasses while Hobbes watches. It's pretty funny on its own, but after Gurren Lagann made its debut, it was noticed that the pair he settles on before his mom sends him back just happens to be green Kamina shades.
The script styling of the Calvinverse makes one strip, which chronicled Calvin discussing how they could become cultural icons on television, much more amusing.
What's more, a throwaway gag from one New Year's strip has Hobbes asking Calvin if their parents celebrate the new year. Calvin notes that their idea of a party is "mixing regular coffee in with the decaf." Then there's the Calvin & Hobbes: The Series episode "New Year, New Disasters", which has Calvin invited to a New Year's party, while Calvin's parents drown their sorrows in cider.
Each collection of U.S. Acres, another Jim Davis comic strip, features an extra page at the beginning of each book. In the second book, "U.S. Acres Counts Its Chickens", this page was "Ole Sayings We Know Well", featuring plays on sayings about farm animals. One of them was "A Wolf In Sheep's Clothing", which showed a wolf whom looked exactly like the wolf from Season 5 of U.S. Acres, which would debut 3 years after the book was published. Another expression was "A Pig In A Poke", and showed Roy Rooster poking Orson in the stomach, making him look angered. 17 years after the book was published, this U.S. Acres fanart was published, which is exactly similar, but with the TV-exclusive character Aloysius poking Orson.
In one comic, Orson read a story to the chicks about a murderer. A year later, the first episode of U.S. Acres, "Wanted: Wade!" aired, and he was possibly reading the same book, as the book he was reading was about a criminal.
In an early Get Fuzzy strip, Bucky doctored one of Satchel's Where's Waldo? books by changing it to Where's Osama?. At the end, a bunch of American troops find him, and presumably kill him, prompting Rob to say "you can't sell this to kids". In 2011...
There's an issue of Twisted Toyfare Theater about Wolverine's busy day-to-day schedule, wherein he guest stars in several comics over the course of the day. At the end, Alan Moore pops in to quote Oscar Wilde, saying the only thing worse than being talking about is not being talked about. Cut to Speedball, sullenly waiting by the phone, hoping he'll get a call from the Marvel Team Up guys. Speedball's next major appearance was in the last arc of Marvel Team-Up — and not long after he became thrust into the spotlight as Penance in the wake of Civil War.
A related TTT gag features the strip "rebooted" and the closing line with Mego Spidey saying "Yeah, like this magazine will last another ninety issues." He turned out to be right.