Early-Bird Cameo

Note: This Trope has been subjected to some misuse. Please read this article before listing it
An Early-Bird Cameo is when characters in an adaptation or remake of an existing work appear or are introduced chronologically earlier than their introduction in the source work, metatextually turning the character into a Chekhov's Gunman. A form of Adaptation Distillation made to appeal to the original work's fans by showing the character early.

Another definition is when characters who will appear in a soon-to-be-made future work make a cameo appearance in a currently-made one. Thus, you see the character without knowing the character's importance, then years later, the character becomes important in their own work as a sort of cross-series Chekhov's Gunman. This does not include instances of Ensemble Darkhorse, however, which is when a character becomes so popular that they stand a good chance of getting their own work. (In other words, this has to be an intentional early appearance.)

See also Continuity Cameo, Production Foreshadowing, and Hilarious in Hindsight. Focusing on these can lead to a Poorly Disguised Pilot. For self-contained works, compare Chekhov's Gunman, where an important character is deliberately introduced as a minor character, and its inverse, Destined Bystander, where a minor character eventually becomes important through Character Development. Vaguely antonymous with Marth Debuted in Smash Bros. Not to be confused with a Call Forward, which is when a prequel references a character or plot device from the original.

Anime and Manga
"Rex: This sucks! I'm gonna go dye my hair."
 * In the first episode of Naruto, all the members of the Rookie Nine are seen lined up for the Henge Jutsu evaluation. Sakura and Sasuke are even shown going before Naruto. In the manga, Sakura and Sasuke aren't shown clearly until a few chapters later (you can see Sasuke in the background of one panel though), after Naruto becomes a Genin, and the rest aren't introduced until the Chunin Exam arc.
 * Some of the dialogue is changed, as Shikamaru and Ino replace the generic students who complain about Naruto's mischief causing them to be tested on Transformation, and Shikamaru wondering why Naruto is among the graduates when they are assigned to teams, when both had been done by generic students who presumably went on to fail their Genin exams. In Episode 3, a few of the teachers appear while observing Naruto and Sasuke in the classroom, including Kurenai, who is incredibly Off Model, has the red and white on her outfit reversed, and has a different voice actor for that episode.
 * In the manga, the Akatsuki member Hidan was only seen clearly when he makes his first appearance in person, but in the anime he makes an appearance that is clearly him as a hologram during the Gaara Rescure requesting to be the one to take care of Team Kakashi.
 * Also Kakuzu as well.
 * In a particularly weird version of this, a Whole Episode Flashback of Jiraiya's has appearance by various ninja who would become back when they were . However, in the manga we only saw one of them this way (another one we saw in the present before the past in both versions), while the rest were introduced in the present tense and mentioned to all be people Jiraiya meet in life.
 * There've been a string of these in the One Piece anime recently; Akainu appeared in the background of a group shot just over a month after his present design was unveiled in the manga, Jimbei was shown among the Warlords quite a ways before his proper, physical introduction, and Shiryuu's shadow showed up in Impel Down long before his existence is even hinted at.
 * Nami appeared in the first few episodes working independently before her proper introduction during the Buggy arc.
 * Kaworu Nagisa, who only appears in episode 24 of the Neon Genesis Evangelion TV series, is seen in the first movie of the new Rebuild of Evangelion tetralogy. This may have something to do with him being an Ensemble Darkhorse, though. He also shows up quite a bit earlier in the manga adaptation, and in pretty much every Alternate Continuity. White Haired Pretty Boy = massive fandom. Notably, however, he's much more clearly a villain in the manga.
 * Every major character appears in the first episode of the 2006 version of Kanon, save for For those who kept trying to spot the Makoto Sawatari we know, it's not her that we see in the pilot episode, but rather, her  is what we see.
 * In the first episode of Eyeshield 21, as Sena wonders what club to join, you can see Monta in the background, presumably stumping for the baseball team. Another early episode features Suzuna Taki, who's trying to track down her brother Natsuhiko; she shows up again during the Death March arc, which is where she first appeared in the manga.
 * Inverted in Tokyo Mew Mew: Minto, Retasu, Bu-ling and Zakuro appear in the beginning of the manga before passing through the Debut Queue, but are removed from the beginning of the anime.
 * Many of the angels that Misaki faces later in Kidou Tenshi Angelic Layer appear on a videotape that Icchan is watching early in the anime.
 * In the anime Mermaid Melody Pichi Pichi Pitch, Caren appears several episodes before she becomes significant to a plot, winning a beauty contest that the main characters and villains entered.
 * Caren notably made a cameo during the beauty contest story in the manga as well, though she did not take part in it like in the anime.
 * In the manga adaptation of Tengen Toppa Gurren Lagann, Nia is shown right after Kamina, Yoko, Leeron, and Simon leave Ritoona Village. There's also some Early-Bird Ship Tease for Dayakka/Kiyoh and Rossiu/Kinon.
 * In Gurren-Hen, makes an appearance just after
 * In Lagann-hen,
 * In Bleach, The opening used during the Bount Arc had a Couch Gag which would show a picture of a different character each episode. One of these showed Grimjow who wouldn't show up until the next story arc. Other characters shown this way include Ulquiorra and Shinji.
 * Chad appears briefly in the second episode, offering to help repair Ichigo's house after the fight against Fish Bone D in the first chapter. In the original manga, he does not appear until Chapter 7 (which is shown in anime episode 4).
 * Similarly, Ishida is shown in art class (sewing, of course) a good six episodes before most of the main characters are even aware of his existence, much less that he's a Quincy.
 * While less noticeable than the other examples, in the anime, Kiyone and Sentarou (Ukitake's bickering third seats) first appear in Ukitake's debut when he hears about Aizen In the manga, a faceless messenger tells him, and Kiyone and Sentarou don't arrive until he calls them out of hiding a few chapters later.
 * Directly after Grand Fisher's loss to Ichigo in the early episodes, he's held down and had his mask ripped off by at least two other Hollows. Two of these were Aisslinger and Di Roy, the latter shows up much later as Grimmjow's weakest Fraccion and the former shows up at the beginning of the Hueco Mundo arc, guarding the underground area of Las Noches.
 * An early version of Shinji Hirako can seen in the first chapter's cover art page in the manga. He wouldn't make his official appearance in the series for another 182 chapters.
 * In the manga of Katekyo Hitman Reborn, the important characters were introduced one at a time. In the anime, Tsuna passes by Ryohei, Yamamoto, and Hibari when he is running to catch up with Kyoko.
 * The first episode of Detective Conan gives Conan's future first-grade friends speaking roles.
 * Rex Raptor/Dinosaur Ryuzaki appears in Toei's Yu-Gi-Oh movie briefly as someone who is defeated by Seto Kaiba. He had pink hair and never appeared in Toei's anime otherwise. Lampshaded in the Other Abridged Movie based on this one:


 * An episode of Urusei Yatsura featured a story in Feudal Japan with the cast playing different characters. Before the story itself begins, the cast breaks the fourth wall to explain what is happening... when all of a sudden Mendou shows up for the first time. When the others ask who he is, he calmly replies "My name is Shutaro Mendou and I will soon become a regular character on this show". He of course, joins the rest of the cast in the story. Sure enough, Mendou's "actual" introduction occurs a few episodes later without any mention of this. If you're going to do a Genji story, someone has to be To No Chujo (Genji's friend/rival), that's Mendo to a "T", continuity be damned.
 * In the Dragonball manga, Pilaf and his henchmen Mai and Shuu aren't introduced until Goku and friends have collected 6 Dragon Balls and reached his castle (Chapter 18). In the anime, he shows up in the very first episode, acquires the Dragon Ball that he has in the manga and for the rest of the arc, their various exploits in attempting to acquire the other Dragon Balls are depicted. Which of course, since Goku and friends get all the rest, Failure Is the Only Option for these exploits.
 * Another case in Dragon Ball involves the introduction of Tenshinhan (Tien) and Chaozu. In the manga, they first turn up at the 22nd Tenkaichi Budokai while in the anime, they first appear as the villains of a filler episode while Goku is doing his solo training.
 * The anime of Yawara added a date scene with Yawara in the park with Kazamatsuri (who's trying to avoid all the girls he stood up)in episode #6. One of them (the one in the boat) is Yoko Nanda, who won't join the main cast until MUCH later (like, after the part that's come to the USA). Nanda's defining characteristic WAS her bad luck with men, so it works rather well.
 * In the Fullmetal Alchemist anime, Maes Hughes first appears during the train hijacking incident and helps Ed and Al retake the train, despite not appearing until Chapter 6 of the manga. The first Brotherhood episode features an entirely new story that features cameos by some of the military characters.
 * In Brotherhood, Izumi and her husband make a brief background appearance behind a scene where Winry is at a train station. Even earlier, when Ed is giving a shortened version of their adventures in a flashback, she appears in silhouette when he talks about them getting a teacher.
 * The same scene contains Mei Chang.
 * Also in Brotherhood, this is inverted with Yoki. His first appearance is reduced to a brief mention, and it gets properly told (uh...somewhat) in episode 39.
 * The first anime had covered Yoki's story well, so it only receives a brief nod in the second to make sure that the climax gets its full time to shine. Yoki's story isn't the only arc covered in the first anime to receive this treatment.
 * Kimblee also appears in the first episode of Brotherhood; Isaac MacDougal offers to break him out of prison, but he refuses.
 * The first anime introduced Lust in the first episode. She's noticeably paler then everyone else, and is draped, so she seems like a passerby.
 * Another inversion happens in Death Note, where L appears at the very end of the first chapter, but doesn't appear until the Interpol conference in the second episode of the anime. An early scene with Near, Mello and Roger (the man in charge of Wammy's Orphanage) is delayed, and they first appear when
 * Also Matt appears in episode 32 in the anime with Mello
 * In the Fist of the North Star anime series, Kenshiro's girlfriend Yuria, as well as his nemesis Shin, appear as part of Kenshiro's recurring nightmares/hallucinations prior to their proper introduction in the story.
 * In the second anime series, the Governor Jakoh is the first character to appear in the anime, whereas in the manga version of the Tentei story arc, he doesn't show up until he is revealed to be The Man Behind the Man.
 * Shion from Higurashi no Naku Koro Ni appear early in the manga. makes a few appearances in omakes arcs before her first appearance. Shion makes an appearance in an omake from the first arc, when she makes her first appearance in the next arc. Likewise for the anime. Hanyuu is The Voice throughout the events of Yakusamashi-hen, and she actually [[media:Hanyuu_outline.jpg|appears as a silhouette behind Rena and Keiichi in the third episode of Kai]].
 * In the first live-action movie, appears behind Keiichi as a silhoulette just before.
 * The Nurarihyon no Mago anime not only has Gyuuki, the first major villain, appear early, but practically has him appear every other minute for no real reason.
 * The end of the first volume of Hellsing Ultimate has a brief appearance by the Major, as well as a brief flash of him while Luke and Jan Valentine are discussing their role in the coming events. The actual manga has him make brief appearances just after the attack on Hellsing headquarters and during the meeting between Integra and Enrico Maxwell, before he is properly introduced to the story (both of these appearances are also in the OVA).
 * In Bakuman｡, Kaya Miyoshi is briefly shown calling for Miho to come with her in the first episode of the anime. She doesn't appear until a few chapters into the series in the manga, when she meets the main characters on the roof. Koogy's music turns up a few times before he decides to make his debut as a mangaka.
 * In the manga adaption of Rusty's arrival in ThunderClan during Warrior Cats, Ravenpaw is in the camp. In the book, he didn't appear until later.

Comic Books

 * When Tintin In The Congo was turned into colour, Thomson and Thompson were added into the scene where he is saying goodbye to everyone on the railway platform (they were not present in the original black and white edition). The pair made their first proper appearance in Cigars Of The Pharaoh.
 * Certain random background Legionaires were changed into Brainiac 5 when early Legion of Super-Heroes stories were reprinted, by simply recolouring them to Brainy's colours (purple clothes, green skin, blonde hair).
 * The graphic novel adaptation of the first Artemis Fowl novel features references to Opal Koboi and her company- both of which play major roles in the second book- that were not in the print version.
 * In the Mega Man comic, the Short Circuits in issue 4 had Proto Man, Rush, Bass, and Treble showing up, demanding their turn in the comic.

Fanfic

 * In Project Tatterdemalion, a Bleach AU in which Hollows are the result of The Virus and shinigami those of its vaccine, a pre-Hollow Nel gets a brief cameo as a coworker of Ichigo's parents who was infected- well before the introduction of Arrancar, or indeed any version of the events of Bleach canon.

Film

 * This can be seen in several super-hero movies wherein pre-transformed allies, sidekicks, or villains may make an appearance, whereas in the comics, their first appearance included said transformation. Billy Dee Williams as pre-Two-Face Harvey Dent in Tim Burton's Batman (though the former was replaced by Tommy Lee Jones by the time he actually became Two-Face).
 * The producers of The Dark Knight Saga originally wanted the DA in the first movie to be Dent, but decided they couldn't give him time to properly develop so they came up with another character instead. This, unfortunately, led the filmmakers to stridently avoid this trope.
 * Dylan Baker as the pre-Lizard Curt Connors in the Spider-Man series.
 * Similarly, Samuel Sterns appears as a supporting character in The Incredible Hulk. His final scene appears to be the start of his mutation into The Leader.
 * Dr. Hank McCoy appears briefly as a talking head on TV in X 2 X Men United, although he appears to be a different character from the Beast who shows up in X Men the Last Stand.
 * Not necessarily - there were plans to show Steve Bacic (who played Hank in X2) growing his fur from the effects of Cerebro at the climax. So there's no problem with them being the same character, if we assume his fur's a more recent development.
 * Though this is complicated by the character's later appearance in X Men First Class, which establishes that he's had fur for several decades.
 * In X2 Hank could possibly be using mask/make-up or a holographic image inductor to disguise himself.
 * A diamond-hard Emma Frost appears in X Men Origins Wolverine but wouldn't appear as a named character until X-Men: First Class.
 * When you consider that X-Men Origins takes place after Vietnam considering the opening credits, the diamond girl in X-Men Origins CAN'T be the actual Emma Frost since the proper character appears as an adult in First Class, several years before the U.S. became active in Vietnam and the film features a cameo of pre-Weapon X Logan as evident by his different hairstyle.
 * Maybe we could retcon her as ones of the Stepford Cuckoos?
 * Also, Kitty Pryde appears in the background of X-Men and runs through walls in X-Men 2 to escape her attackers but isn't given a name until X-Men 3: Last Stand, where Ellen Page becomes the third actress to play her.
 * Several X-Men characters, including Jamie Madrox, appear on William Stryker's computer in X-Men 2. Also, there appear to be a set of X-rays showing wings similar to those of Warren Worthington. Both characters appear in X-Men 3.
 * First Class has a montage of Charles and Erik recruiting mutants found using Cerebro. At one point they try to talk to Logan (Wolverine) and get blown off before they can say anything, since he was around at the time but doesn't join until much later.
 * Blink and you'll miss it, but a young girl version of Storm can also be seen when Charles is using Cerebro to find other mutants.
 * The updated version of Star Wars: A New Hope has Boba Fett showing up in an added scene, though he's not significant until the next movie.
 * The planet Coruscant from the prequel trilogy is shown during the celebration sequence in the Special Edition of Return of the Jedi. The DVD version even adds buildings seen during the prequels.
 * In the film version of Voyage of the Dawn Treader at the end we hear Aunt Alberta call up "Jill Pole's stopped by for a visit". Jill becomes an important character in the next story The Silver Chair.

Literature

 * The War Craft novels Tides of Darkness and Beyond the Dark Portal, novelizations of the Real Time Strategy Warcraft II and its expansion respectively, have this in spades, not only featuring characters from that time period that were only introduced in Warcraft III and beyond, but also updating the story itself in the light of retcons and heavy additions to the canon in later games. They're almost "the Second War as seen through the prism of World of Warcraft". Let's just say that the flashback in The Frozen Throne in which Gul'dan wanders into the Tomb of Sargeras is recited almost verbatim in the first book, and Auchindoun plays a much more extended role in the second, along with the introduction of the "new" draenei.
 * Those Doctor Who Novelisations that were published some years after the TV story was broadcast sometimes added in references to later stories. For instance, in the novelisation of Terror of the Autons, the bomb that the hypnotised Professor Philips uses to try to kill the Doctor and Jo was retconned into a Sontaran hand grenade. And there's the notorious line in the novelisation of The Time Meddler where the Doctor refers to the Monk as a Gallifreyan, leading fans who relied on the novelisations to believe that the Doctor's home planet had been named eight years earlier than it was on TV.

Live Action TV

 * In Power Rangers Jungle Fury The main villain Dai Shi shows up in the fist episode. Much earlier than his Juken Sentai Gekiranger counterpart who doesn't show up until  and isn't revealed as the villain until near the end.
 * I Claudius did this in combining the novels I, Claudius and Claudius the God -- a large part of the latter discusses Claudius' childhood friend and ally Herod Agrippa, despite the fact he is absent for much of the former, even though it is about this period of Claudius' life. For this reason, the television series introduces Herod as a character long before Claudius becomes emperor.
 * True Blood has done this with a number of characters and concepts, most notably Sophie-Anne, the vampire queen of Louisiana, who has a cameo in season two of the series but isn't introduced until the sixth book. The last episode of season two also raises the question of "what" Sookie is, something that isn't asked, much less answered, until the later books.
 * Almost every DC Comics characters on Smallville, most notably a proto-Justice League.

Theater

 * The Royal Shakespeare Company is fond of doing this to Launcelot Gobbo, the "fool" from The Merchant of Venice. The 1999-1994 run (with Christopher Luscombe in the role) combined the two "Prince of Morocco" scenes, so that Launcelot's first appearance came directly after the scene in which the bond is agreed to. He was depicted doing odd jobs around Shylock's office (preparing coffee and rearranging files) until the others exited, at which point he suddenly stepped out and gave his monologue--probably quite a surprise to audience members who thought he was just an extra! The current run gives him an even earlier cameo--the show's setting has been transposed to Las Vegas, and there's an Elvis impersonator walking around singing appropriate music. Guess who he turns out to be...
 * The Things I Will Not Do When I Direct A Shakespeare Production, On Stage Or Film, #225: "I will not incorporate an ominous witch-doctor woman into Romeo and Juliet, having her stalk the streets of Verona until she's finally revealed as the apothecary."

Video Games

 * In the Ace Attorney case "Rise from the Ashes" (inserted at the end of the first game when it was updated from the Gameboy to the DS), Gumshoe gives Edgeworth a menu from a French restaurant that's just opened. You have to squint a little, since the pictures is tiny, but the man on the menu is Jean Armstrong. Armstrong and his French restaurant don't show up until the third game.
 * Then again, in Japan, they've got the first four cases of the first game, and the two other games as the Gyakuten Saiban trilogy for the GBA. The fifth case was added in the DS remake, which came later, hence his apparition.
 * It introduced a Dub Induced Plot Hole in the french version, which tried to make Jean Armstrong sound less French, for obvious reasons. He was made Libanese in this cameo, but Italian in the third game, when translated there.
 * Yoshi made retroactive cameos in the Super Mario Bros. trilogy by way of video game remakes. In Super Mario Bros. DX (a remake of the first Super Mario Bros.), there's a block hidden in each level in Challenge Mode, each holding a Yoshi egg. Collect it, and Yoshi will hatch out during the point tally. When Super Mario Bros 2 was remade as Super Mario Advance, you can unlock an extra mode where you can find two Yoshi eggs in each level. Find all the eggs in each world, and Yoshis would hatch out of them. Finally, Super Mario Bros 3 was remade for Super Mario All-Stars and as Super Mario Advance 4, and in both versions, the King of World 7 had been transformed into a Yoshi rather than a Piranha Plant.
 * A more straight example from that game would be the fact that the sprite used for the last example mentioned would later be used for the main sprite for Yoshi in Yoshis Island.
 * Which actually previously appeared in the SNES version in Yoshi's Cookie, depending on your region.
 * In Mega Man Powered Up, a remake of Mega Man 1, there is an option to play as Proto Man, who did not appear in the series' original run until Mega Man 3.
 * The OAV prequel included with Mega Man X: Maverick Hunter X features a few cameos by characters who appeared in the later games of the series. Signas, who becomes commander of the Maverick Hrizzly Slash and Commander Dragonfly, bosses from the fifth and sixth games respectively, are seen during a mission briefing as current hunters. Presumably one of the generic humanoid hunters is the Green Biker Dude, Memetic Badass Extraordinaire.
 * In Sonic the Hedgehog, Knuckles is playable in Sonic 2 as part of the Sonic 2 and Knuckles setup.
 * Cream the Rabbit can be spotted in Sonic Adventure as an Easter Egg via a remake.
 * In the Anniversary remake of Halo, 343 Guilty Spark is introduced in a terminal message where he warns you that your ship is getting too close to the ring. The rest of the terminals delve into his backstory.

Web Comics

 * In Sailor Moon CS, Minako can be seen briefly in issue 4.
 * A Miss Meioh appears in issue 2.

Western Animation

 * In the Legion of Super Heroes cartoon, before he joined the Legion and coined his superhero name in The Substitutes, Matter-Eater Lad was a competitor in the Space Olympics episode "Champions." The other, rejected lame-power applicants also showed up in Lightning Storm for comic relief. Ultra Boy makes his first appearance as a competitor in Champions, as well.
 * Batman the Animated Series established Harvey Dent as Gotham's DA and a friend of Bruce Wayne in two episodes before he has the accident that melts his face off.
 * The Spectacular Spider-Man: not only gives Eddie Brock an extensive role (influenced by his role in Ultimate Spider-Man), but also has Norman and Harry Osborn, The Sandman, The Rhino, The Shocker, Doctor Octopus, Curt Connors, and, possibly,, as supporting characters or minor villains before their inevitable darker turns, as well as, as said before, every named schoolmate Peter had in the comics, as well as (again, as noted above) Gwen Stacy, whose fate is well known. Felicia Hardy also cameos in costume in a Halloween Episode before her official introduction.
 * Cletus Kasady (Carnage's host) makes a cameo in the Christmas episode, had the series continued he probably would've become a recurring villain.
 * Morris Bench (Hydro-Man in the comics) and Roderick Kingsley (Hobgoblin in the comics) also made appearances, and Mac Gargin (Scorpion in the comics) was mentioned at one point. Had the series continued, all three villains would have likely been used.
 * Miles Warren also makes recurring appearances as an amoral and cold-hearted scientist who gradually takes over Curt Connors' lab, during which time he makes it clear he's interested in gene-splicing by transforming Kraven the Hunter. Had the series gone on he would have become the supervillain The Jackal (who splices his DNA with a jackal late in the comics) and probably done their version of the Clone Saga. They also point out that he is the brother of Peter's high school science teacher.
 * Also, a girl seen at the school dance in the seventh episode later becomes a recurring character in the second season: Sha Shan, Flash Thompson's would-be-girlfriend.
 * Both animated versions of Horton Hears a Who could actually be this to the Grinch, since the book both animations were based on predated the book version of How the Grinch Stole Christmas.

Anime/Manga

 * In the first ever episode of Pokémon, Ash catches a glimpse of a large golden bird flying through a rainbow. That bird was only revealed with the arrival of the second generation as Ho-oh, a legendary bird Pokémon; his colors changed a lot since then. It is actually a habit within the franchise to show a new Pokémon specimen in the anime or in movies before it's actually available in the current games. Togepi, Marill (and its pre-evolution Azurill), Snubbull, Kecleon, Lucario and Munchlax are only few examples of this phenomenon.
 * For non-character examples: the first movie's Big Bad, Mewtwo, uses Shadow Ball, a generation before it's introduced. Likewise, Green from Pokémon Special also had Pokémon who know 2nd generation moves and used them in the RGB saga, again before the 2nd generation introduces them.
 * Also from the first movie - Ash fights the then-not introduced Donphan during the opening credits and it uses another move from the next generation, Rollout. Neither Donphan nor Rollout were even named in the movie.
 * Elekid, Ledyba, Lugia, and Slowking appeared in the second movie (set during the Orange Island saga and before Gold & Silver and the Johto saga came out).
 * Not to mention the new Generation V Pokémon, Zoroark and its pre-evo, Zorua.
 * Chatot also debuted in Season 9, prior to the release of the Generation IV games.
 * The last few episodes of the original series primarily featured Blaziken (a large chicken-like Pokémon). Blaziken is actually the final evolved form of the Generation III Fire-type starter, Torchic.
 * One of the opening themes for the Advanced Generation arc featured a Gardevoir, yet none of the episodes that used this opening ever featured such Pokémon.
 * In the Lime-iro Senkitan OVA, characters from the series' direct sequel, Lime-iro Ryukitan X, appear. Major Gamou, lead heroine Tsumugi Shima (and her Raimu), as well as one of the villainesses, Linen (though she's unvoiced), all appear for the first time, not only before their anime series, but before their game was released as well.
 * At the end of the final episode of Mai Hi ME, Arika, the lead of Mai Otome, runs across the screen in the background.
 * Also in the second episode you can see a girl who looks almost exactly like Nina sitting in the seat next to Mai and in front of Yuuichi. (She also is in the lineup of girls in the opening credits)
 * Arika is shown in slightly more detail in the last chapter of the Mai-Hime manga, apparently meeting with some school officials to discuss enrolling.
 * The final battle of G Gundam includes cameos by many Gundam from other series (as well as Daitarn 3 and Zambot 3)...including Wing Gundam and Talgeese whose show had yet to air! Similarly, Gundam vs. Gundam NEXT introduced the hero and eponymous Gundam from the novel Gundam Unicorn before the anime adaptation had ever aired.
 * The first or second English Dragonball Z opening had adult/future Trunks in the title slide at the very end, despite him not being introduced until several arcs, and a Big Bad or two, later. Showing up at other points in the intro are Super Saiyan Vegeta and Mecha Frieza (who is getting sliced apart by Super Saiyan adult/future Trunks.) long before their English debuts.
 * Zone of the Enders: IDOLO was created as a prequel OAV to the Play Station 2 game Zone of the Enders. In it, scientist Rachel Links looks at a Fatal Family Photo of her estranged husband and children, reflecting that she wished she could seem them again. It is a small scene in the OAV, but the full-length series that came after centered on her husband James trying to reconcile with their children and seek her out.

Comic Books

 * In the Heroes graphic novels, Sparrow Redhouse makes a brief cameo in a season one issue, about two years before her proper debut in the "Rebellion" story arc (which also retconned an unnamed, masked extra from the TV series as being her).
 * The Protectobots, Aerialbots, Stunticons, and Combaticons in the Marvel Transformers Generation 1 comic first appeared in Buster Witwiky's dream in a UK Filler story before their proper debut in the US comic.
 * This happened to the new Aqualad in Young Justice - the version for the animated series was created first, but his comic-book counterpart first appeared in June 2010. The series premiered January 2011.
 * Barbara Gordon Batgirl had a similar story.

Film

 * In Lilo and Stitch, as Pleakly and The Grand Councilwoman are using the lift to go to Jumba's cell, you can see Dr. Jacques von Hämsterviel in a cell to the right.
 * Kamen Rider Double aided in a fairly important battle in Kamen Rider Decade's first movie before his series premiered.
 * What's more, he came out of nowhere, single-handedly defeated the Big Bad (who was whomping two Riders who could singlehandedly destroy a single universe), and then left. The other riders compacted on that with their own Crowning Moment of Awesome, but still, ain't that application of The Worf Effect taking promotions too far? (As further evidence, when Double joins up for Decade's final battle in the Decade Grand Finale movie, he's been brought down to saner power levels.)
 * Double's movie, Double Forever: A to Z: The Gaia Memories of Fate, featured the debut of his successor, Kamen Rider OOO.
 * Kamen Rider Fourze does the same in OOO's summer movie, crash-landing in the middle of a fight.
 * Super Sentai has been doing the same thing as Kamen Rider in recent years as well. Both Tensou Sentai Goseiger and Kaizoku Sentai Gokaiger showed up for a quick battle cameo in the teamup movies of the two teams before them (both of which involve Samurai Sentai Shinkenger as one of the teams), a month or so before each of their shows started.
 * The next team, Tokumei Sentai Gobusters, make their early-bird cameo in the crossover between Gokaiger and Space Sheriff Gavan.
 * The obscure made-for-TV film Cucumber Castle, based on the Bee Gees' song of the same title and starring Barry and Maurice Gibb, features an appearance by a familiar-faced child - Andy Gibb, then ten years old.

Live Action TV

 * Played with in Witchblade: Gabriel Bowman is first introduced in the third episode of season one (not counting the pilot movie); then, in the second season premiere, which is a same-but-different retread of the events of the pilot, he's shown to have been present at the shootout in the museum, and ends up meeting Sara a lot earlier than he did the first time. Which would make him a kind of Destined Bystander as well.
 * The titular character of Hey Arnold actually first appeared in a stop-motion skit featured in Sesame Street.
 * Cookie Monster actually made his first appearance in a skit featured in The Ed Sullivan Show (which itself was based on an old instructional film by IBM), where he is shown taking a machine apart piece-by-piece and eating it, only to realize that doing so will cause the machine to self-destruct within his body, causing him to explode. And for some reason, this version of Cookie Monster has fangs, while the one in Sesame Street does not.

Music

 * Before her official breakout, Kesha appeared as the uncredited backup singer on Flo Rida's "Right Round". She was also one of the dancers in Katy Perry's "I Kissed A Girl" video.
 * Similarly before Katy Perry's breakthrough with "I Kissed A Girl", she appeared (also uncredited) as Travis McCoy's girlfriend in the video for Gym Class Heroes' "Cupid's Chokehold" (as she actually was McCoy's girlfriend at the time)
 * The liner notes for Guns N' Roses' Appetite for Destruction include the lyric "With your bitch slap rapping and your cocaine tongue you get nothing done", a lyric for "You Could Be Mine" (which was recorded in their next album). Also, the notes for Use Your Illusion I have "Ain't It Fun?", the title of a song they covered in The Spaghetti Incident?.
 * My Chemical Romance's debut album, I Brought You My Bullets, Your Brought Me Your Love, have the french phrase "Merci pour le venin" written on the liner notes. It is the french title of "Thank You For The Venom", a song appearing on their second album, Three Cheers For Sweet Revenge.
 * They Might Be Giants' "On Earth My Nina", released on 1999's Long Tall Weekend, was a reversed acapella version of "Thunderbird", which wasn't released until The Spine five years later.
 * Several years before Jeremy Dawson and Chad Petree founded Shiny Toy Guns, the chorus lyrics of "You are The One" appeared in a trance song called "Neo(The One)" that they produced under the name Slyder, and which appeared in Grand Theft Auto 3 on the Rise FM station.
 * A year before Pearl Jam's debut album, Eddie Vedder could be heard singing backup on Temple Of The Dog's self-titled album, as well as getting a full on duet with Chris Cornell on the song "Hunger Strike". Temple Of The Dog and Pearl Jam shared most of the same lineup, and Vedder ended up on the Temple Of The Dog album after auditioning for Pearl Jam.
 * Da Yoopers had "Cowboy" Dan Collins sing backing vocals on two albums several years before he became an official member.
 * One of Shania Twain's earliest works was singing backing vocals on a 1993 album by Sammy Kershaw.
 * The live film produced from Michael Jackson's 1988 Japanese performance features Michael performing "I Just Can't Stop Loving You" with one of his back-up singers from the tour - Sheryl Crow, whose fame was still several years away.
 * The 1971 album Ram by Paul and Linda McCartney had a ukelele-driven segueway song called "Ram On (Reprise)" on side two. On the fadeout, you can hear Paul launch into a few lines of "Big Barn Bed", which would be the first song on Wings' second album, Red Rose Speedway (1973).
 * Early copies of Radiohead's Kid A included an extra booklet behind the CD tray as an Easter Egg. Some of the cryptic text included in said booklet turned out to be lyrics to songs that would appear on Amnesiac, which was recorded during the same sessions.

Professional Wrestling

 * CM Punk appears as one of the gangsters in John Cena's entrance at Wrestlemania 22.
 * Before he got his "Irish" gimmick in 2006, Dave Finlay was the Divas' trainer and made occasional appearances at WWE events as a nameless official. Watch the part of the 2005 Royal Rumble in which Shawn Michaels eliminates Kurt Angle in less than a minute. Angle retaliates by reentering the ring, eliminating Michaels in turn, and then violently whaling on him. Several referees and other enforcer characters run out to subdue Angle, and one of them is Finlay.
 * In an interview with Beth Phoenix for IGN, a few FCW divas can be seen wrestling in the background. One of them is current WWE Diva Alicia Fox.
 * Both Ivory and Victoria appeared as the Godfather's Hos before they actively started wrestling on the roster.
 * Both of the Hardy Boyz wrestled regularly on WWE TV during the 90s as random jobbers before getting properly called up in 1999.
 * Jacqueline wrestled a couple of matches on Heat against indie wrestler Starla Saxton in 1998. Two years later, Saxton would join the WWE roster officially as Molly Holly.
 * In 1985-86, a 25-year-old Dean Malenko worked for the WWF as a referee. This was 15 years before he would officially debut as part of the Radicalz, possibly the longest time between cameo and appearance on this list.
 * He also showed up in WCW before he officially debuted, as he and his brother Joe took part in the NWA tag team Tournament against Ricky Steamboat and Nikita Koloff at Clash of the Champions XIX in 1992.
 * In a similar example to the Dean Malenko one above, Teddy Long was a referee for years in WWE before becoming a proper onscreen personality, going from valet to Smackdown General Manager.
 * Melina Perez in her pre-MNM days made two appearances on Raw in late 2004, first in a lingerie strip tease segment and then a limbo segment, about four months before she properly debuted on television.
 * She was also one of the few who didn't make the cut in season 3 of Tough Enough.
 * Diamond Dallas Page was driving Rhythm and Blues' pink Cadillac at Wrestlemania VI in 1990, 11 years before he signed with the company.
 * Before debuting his Evil Foreigner gimmick in 2003, French-Canadian wrestler Sylvan Grenier was supposedly a WWE referee tasked with mediating the rematch between Hulk Hogan and The Rock at that year's No Way Out (which, appropriately enough, was being held in Grenier's hometown of Montreal, Canada). This is an unusual example in that Grenier was here referred to by name by the commentary team, and his behavior in the course of the match was actually his Start of Darkness and even carried over to WrestleMania XIX the following month!

Tabletop Games

 * In the Yu-Gi-Oh! Trading Card Game, Wattdragon first appeared as a picture on a scroll in the artwork of Ancient Rules way back in Strike of Neos, over five years before its own release in Galactic Overlord. Its flavor text even makes a reference to "ancient rules" which forbid its capture.

Theme Parks

 * Three examples from Disney Theme Parks. Sleeping Beauty's Castle was opened in Disneyland several years before the movie. It's Tough To Be A Bug, starring Flik and featuring Hopper, was introduced at the Animal Kingdom several months before A Bugs Life opened. Finally, Countdown to Extinction featured Aladar and a Carnotaurus about two years before Dinosaur premiered, at which point the attraction was renamed after the movie.

Toys

 * The Transformers Prime series is not supposed to get toys until after the Dark of the Moon line has been out for a while. But a few of the major players (Optimus, Bumblebee, Megatron, Starscream, & Soundwave) got each got a toy in the Generations line.
 * Sunstorm and Acid Storm originally appeared as unnamed Seeker jets in Transformers Generation 1, and didn't get toys and names until the Universe toyline two decades later.

Video Games

 * Asagi might be the ultimate example of this. Of course, we don't know if she's ever actually going to GET her own game or if Nippon Ichi is just screwing around.
 * While we're on the topic of Nippon Ichi, it's probably no coincidence that Makai Kingdom will be getting a PSP remake after Overlord Zetta's cameo in Disgaea 4, which is the first time since Makai Kingdom that he has actually appeared in humanoid form. The new character from the remake, Petta, will appear in Disgaea 4 as Downloadable Content.
 * Roy's our boy! Before his own game comes out, even!
 * The Gekko from Metal Gear Solid 4: Guns of the Patriots appeared in Super Smash Bros. Brawl, which in some regions was out months before the former game was even released. For that matter, the entire Shadow Moses Island stage is a reference to an entire chapter in the game. Interestingly enough, MGS 4 is a PS3-exclusive game, meaning a first-party Nintendo game is promoting a game not available on a Nintendo system.
 * Old Snake also made a cameo before his official debut, as the most statistically-powerful bonus character in Metal Gear Solid Portable Ops +.
 * Metal Gear Acid 2 beat both games by featuring Metal Gear Solid 4 trading cards two years before the game was even released (granted, they were based on the very first trailer that was released).
 * Metal Gear: Ghost Babel, which was released a year before Metal Gear Solid 2, featured an extra game mode where the player controls a newly recruited soldier who undergoes VR training by having to complete harder versions of Solid Snake's missions in the main game. The name of this agent is revealed at the end to be "Jack", the same name of the protagonist in MGS2.
 * Metal Gear Solid: VR Missions featured a hidden concept art of Metal Gear Ray from Metal Gear Solid 2.
 * Cyborg Ninja Raiden played a cameo role in Metal Gear Solid 2: Substance. However, it's not the same Cyborg Ninja suit Raiden wears in Guns of the Patriots, but more of a cosplay of him in Gray Fox's exoskeleton suit from the first MGS.
 * Galen Marek, aka Starkiller, Darth Vader's secret apprentice and protagonist of Star Wars: The Force Unleashed, made a playable appearance in Soul Calibur IV three months prior to the release of his game. He goes simply as "The Apprentice" in SCIV.
 * The Big Bad of Ace Attorney Investigations 2 appeared very briefly in the intro to "Farewell, My Turnabout" as Global Hero Onyankopon.
 * Merrill and Isabela are both retroactively being turned into this by their appearance as party members in Dragon Age 2.
 * In Space Invaders Extreme (available on both PlayStation Portable and Nintendo DS), Mr. ESC from Exit makes a cameo appearance when you select the Exit option. While Exit was already released on the PSP at the time, and the DS version of the game was already available in Japan at the time, the DS Space Invaders Extreme appearance is a legitimate Early-Bird Cameo in North America.
 * The Kyo clone Kusanagi initially showed up in The King of Fighters 2002 as an alternate moveset for Kyo, but did not receive a role in the story proper until the next game, 2003.
 * Nearly half a year before he became the protagonist of his own game Luso Clemens showed up as a minor playable character in the remake of the original Final Fantasy Tactics, War of the Lions, even though the games are on competing systems. In what is either this or an Ascended Extra, Hurdy, a main character from A2, first appeared as an operator of the teleporting services in Final Fantasy XII.
 * In the game Super Mario Galaxy, Yoshi's head actually makes cameo appearances as two planets in the game: one on the save file screen, and the other in "Space Junk Galaxy." Guess who ended up appearing in the sequel!
 * Also, the rock power-up from the sequel actually first appeared as one of Bowser's attacks during the final boss battle.
 * Dengeki Gakuen RPG: Cross of Venus has an actor variant of this trope: being a Massive Multiplayer Crossover video game based on several Light Novels, it manages to get the voice actors of the featured series' anime adaptations to reprise their roles. This includes the voice cast of Asura Cryin', which adaptation premiered a few days after the game's release.
 * On the Street Fighter side of things, X-Men vs. Street Fighter snuck in Shadaloo-era Cammy as a playable character before the Alpha series got to introduce her proper in Alpha 2 Gold.
 * Dan Hibiki also appears as a random design that was expected to go unused in some old artwork poking fun at SNK's Art of Fighting series. He later became an official, secret character in Street Fighter Alpha.
 * Balrog and Vega made cameos in Sagat's endings in the first two Alpha games, while E. Honda appeared in Sodom's ending in Alpha 2. All three of them would appear as playable characters in Alpha 3. Fei-Long also made a cameo as a spectator at Dan's stage in Alpha 2, but he wasn't included in Alpha 3 until the console version.
 * Rolento and Cody made cameos in the first and second Alpha games respectively before they became playable in Alpha 2 and Alpha 3 respectively.
 * Chronologically, Street Fighter IV is set before Street Fighter III Yun and Yang appear in Chun Li's opening story sequence in the console version. They later appeared as playable characters in the arcade version of Super Street Fighter IV.
 * In Strong Bad's Cool Game For Attractive People, a squirrel from Wallace and Gromit's Grand Adventures appears on one of Strong Bad's unlockable shirts.
 * Chicken Little hadn't come out yet in Japan when Kingdom Hearts II was released, but was a summon in the game.
 * Also, according to this game, Ursula's lair is actually made from the skeleton of a dead Leviathan. Considering that The Little Mermaid was released in 1989, that means that the Leviathan wouldn't even make his official debut until 2001's Atlantis: The Lost Empire (another animated Disney movie focusing on an underwater civilization, which featured him attacking the very ship the heroes were in at one point), released 12 years later.
 * They could have meant the Final Fantasy Leviathan.
 * The appearance of Alfred the Pilot in Real Bout Fatal Fury 2 was meant to be a tie-in for his own game, a Play Station-exclusive port Real Bout Fatal Fury Special subtitled Dominated Minds, but since that game was only released in Japan, many people think he was simply a character made up for Real Bout 2. In Hon-Fu's and Yamazaki's endings, the antagonist from Dominated Minds, White, can be seen.
 * Rock Howard, the protagonist of Garou: Mark of the Wolves, appears in Terry's ending in Fatal Fury 3.
 * The Oukaou and Nanajin from Wings Of Rean both appear in Another Century's Episode 2, which came out a few months before Wings Of Rean premiered.
 * There are references to Lezard Valeth and Lenneth Valkyrie in Star Ocean the Second Story. Valkyrie Profile would not be completed for another two years after Star Ocean 2 was released.
 * Pokémon XD is a third-generation game. It features a non-playable Munchlax and a sorta-playable Bonsly, both fourth-generation Pokémon.
 * Munchlax appears as a playable character in the original Pokémon Mystery Dungeon Rescue Team games via cheat codes. The player can also get statues of Lucario, Weavile, Bonsly and Mime Jr. placed outside their house.
 * Also in the original PMD, Munchlax walks through the square as a random event.
 * Munchlax also appeared in the game Pokémon Dash.
 * Rock Band 2 had the album release of Shackler's Revenge a few weeks before the album it was on (Chinese Democracy) was released.
 * Sonic the Hedgehog appeared as an air freshener in the racing game Rad Mobile two months before the first Sonic game.
 * Sonic the Hedgehog 2 was first previewed in pre-alpha form on Nickelodeon's Nick Arcade, several months before its release.
 * The tune for "Sonic - You Can Do Anything", the Japanese/European opening of Sonicthe Hedgehog CD, was first used as the BGM to Green Hills Zone in the Master System/Game Gear version of Sonic the Hedgehog 2.
 * The  are first shown in Team Dark's ending in Sonic Heroes. They later appear as actual enemies in Shadow the Hedgehog.
 * Banjo, Tiptup, and Conker in Diddy Kong Racing. Timber was also supposed to have his own game with Bumper and Pipsy as his sidekicks, but it was canceled.
 * Also, from the same game, there's Krunch, a neutral member of the Kremling Krew from Donkey Kong Country. Although he never appeared in another game, nor did he ever seem destined to, his design and attire were based on the Kremlings in the then-unreleased Donkey Kong 64 as opposed to the original SNES trilogy.
 * Although she did not appear in person in that game, Kazooie was actually first mentioned in the game instructions manual for DKR.
 * In the Crash Bandicoot series, Nina Cortex's official debut was in Crash Twinsanity. However, the Fusion crossovers with the Spyro the Dragon series were released before it and introduced her as a radically different character.
 * Also, Fake Crash, a joke expy of the main character, first appears after 100% completion in various locations of Crash Bandicoot 3 Warped before his first playable appearance in Crash Team Racing.
 * The Naboo Starfighter appeared as a secret ship in Star Wars: Rogue Squadron six months before the release of The Phantom Menace.
 * Amazingly, this code managed to remain hidden until after the movie came out. Whether or not this subverts the trope is debatable.
 * Geese Howard of Fatal Fury fame makes a cameo in the extended ending of the SNES version of Art of Fighting, which was released months before Geese's actual appearance as the True Final Boss in the arcade version of Art of Fighting 2.
 * Persona 3 Portable features a man drinking at the nightclub in Paulownia Mall. He appears to be Vincent from Catherine. He tells you a bit of a story about how much of a Jerkass he is, then points out that it has "nothing to do with your problems" at the end.
 * Trixie from the Back to The Future game appears in Poker Night At the Inventory, facing away from the camera.
 * Eoleo, one of the playable characters in Golden Sun: Dark Dawn, briefly appears as a toddler in Golden Sun: The Lost Age.
 * In Silent Hill 2, James can find a newspaper article about Walter Sullivan - a character who doesn't show up in person until Silent Hill 4.
 * Digimon World 3 featured Agunimon, KendoGarurumon, and AncientGreymon in cameo appearances as DNA Digivolutions; all three Digimon would go on to play large roles in Digimon Frontier. However, it's slightly complicated; Frontier wasn't released in some regions, while in Japan, World 3 was released three months into Frontier's run.
 * In the first Resident Evil, you find a letter to Ada {Wong} from her boyfriend John (who was turning into a zombie), which you use to solve a puzzle.
 * Kite (Sora), an unlockable extra character in .hack//Link, is the main character in .hack//TheMovie.
 * The Fairly Oddparents PC game Breakin' Da Rules! features a level where Timmy has to avoid a younger-aged version of Vicky and Tootie's mom, named Nicky here. The character eventually appeared on the show in her adult form, alongside her unnamed husband, in the "Channel Chasers" movie.
 * In Grand Theft Auto IV, you see Luis Lopez and Johnny Klebitz from the two expansion packs, "The Lost and the Damned" and the "Ballad of Gay Tony". You can actually kill Luis without failing the mission, too.
 * In the mission I'll take her, where you kidnap Gracie Ancelotti, she screams, fights, and talks a lot of smack. If you drive long enough she even makes a reference to her "Gay friend, Tony." It's obvious who she's talking about.
 * Super Smash Bros. Brawl serves as one for Kid Icarus Uprising, albeit somewhat retroactively (Uprising was originally a completely unrelated game until the dev team thought that Pit & co. would be a perfect fit for their concepts). Pit and Palutena's updated looks are used in Uprising, as well as Pit's bow-twin swords weapon. His Fallen Angel Palette Swap from the game, on the other hand, became an actual character. It should be noted that Masahiro Sakurai of Kirby fame helms both the Super Smash Bros series and Kid Icarus Uprising.
 * The PC port of Halo 2 includes a silenced version of its SMG in a test map. This silenced SMG later went on to be the primary weapon of the player character in Halo 3 ODST.
 * Lumi, the virtual Distressed Damsel of Child of Eden, previously appeared in Lumines II in late 2006, which also featured "Heavenly Star", the debut song of Genki Rockets, the semi-fictional band that Lumi is the "singer" of.

Web Original

 * Occurs from time to time in Survival of the Fittest. Friends and relatives of characters from previous versions occasionally appear in the game, usually having been mentioned in said previous version. One of the most notable examples of this trope, though, would be Yelizaveta "Bounce" Volkova, who first appeared as a character in the In-Universe chatroom, and then made an official appearance in v4.
 * In Trinton Chronicles the villains known as Trinity make a minor appearance at the end of Fantasia before becoming the villains of the next story. By that same token, a character from another furry-based game called Arcadia makes her pre-Trinton appearance here before plopping into Trinton Chronicles two years later.
 * Iron Liz appeared without introduction in the Warrior 2-3 review on Atop the Fourth Wall remarking "Who the hell am I?".
 * In his review of Caligula to celebrate 100 episodes, The Cinema Snob had appearances from all of Brad Jones's other characters, including 80s Dan... at least, until Brad pointed out he didn't have an 80s Dan character, at which point Dan faded away into nothingness. A few weeks later, 80s Dan became an official spin-off.
 * 'The lame girl with the spirit of the squirrel ' was a throwaway line in some early Whateley Universe stories. Then she was a weak character in some of the Phase stories, where she was in Phase's aikido class and gained the name Aquerna. Now she's had a vignette, a novel, a Crowning Moment of Awesome, a Crowning Moment of Funny, and a Crowning Moment of Heartwarming.

Western Animation

 * Pixar started doing this in Monsters Inc., where we see Boo holding Jessie, the ball from Luxo Jr. and... Nemo, who only debuted 2 years later). Every Pixar feature since has featured a Sneak Peek.
 * Nemo also appears in Monsters Inc. as a fresco in the sushi restaurant.
 * In Finding Nemo, a kid can be seen reading a comic book of The Incredibles.
 * Dug the dog from Up makes an early appearance as a live shadow on a wall in Ratatouille.
 * In a DVD bonus short for Ratatouille, WALL-E makes a brief cameo as a Mars rover operator. Parodied on WALL-E's website, which shows him hiding in every single past Pixar movie.
 * There's a similar gag documentary on the Lilo and Stitch DVD - apparently Stitch has been attempting to get a Disney movie since 1937. The documentary shows screenshots from films with Stitch drawn in them.
 * Up: When Carl's balloon-house goes past a little girl's bedroom, a teddy bear is in the far left corner of the screen. This is Lotso(-Huggin' Bear), who is an important character in Toy Story 3.
 * In Toy Story 3, one of the posters in Andy's room shows a car that is an upcoming character in Cars 2. Additionally, he has a "Newt Crossing" sticker next to his computer; Newt was a Pixar film that was cancelled in development.
 * Cars 2 has car-versions of Princess Merida and her family on a glass window in the British pub.
 * Okuni, Shigeko, Tamiko, and Shu Todoroki in Tokyo Mater.
 * A statue of a cherub appears in Aladdins "A Whole New World" that later shows up in Herculess "I Won't Say I'm In Love". I also can't help but think the coincidental Sphinx and the horses are also shout-outs, but that's ridiculous. The song actually ends with Aladdin and Jasmine watching fireworks in China.
 * At the very beginning of Pinocchio, you can actually see two books in the background entitled Alice in Wonderland and Peter Pan, respectively.
 * Although they got their own animated TV spinoff called The Emperors New School, Kuzco and the gang actually all made their televised debuts in the show House of Mouse.
 * House of Mouse also for some reason, portrayed Ronno as a fawn instead of an adult deer since Bambi is always portrayed here as a fawn as well. Young Ronno won't make his official appearance in any animated Disney work at all until the release of the Direct to Video film Bambi II.
 * Ralph the Guard, a regular on Animaniacs, made his debut as an unnamed, surprisingly competent security guard in several episodes of Tiny Toon Adventures. Likewise, World's Oldest Woman and Lucky Bob, two characters on Histeria, made cameo appearances in Animaniacs segments years before their own show premiered. Histeria's version of Joan of Ark also first appeared on Tiny Toons.
 * Darkwing Duck and Gosalyn could be seen in the opening sequence for the first season of The Disney Afternoon, about a year before their own show started airing.
 * Similarly, in its second season, Marsupilami frequently appeared in The Disney Afternoon's commercial bumpers a year before Disney released his cartoons.
 * Five years before the first episode of South Park aired creators Trey Parker and Matt Stone made a short film called The Spirit of Christmas, which was made using construction paper and had prototypical and mostly unnamed versions of the show's main characters. Two years later they made another Spirit of Christmas, this time with the show's main characters properly named, characterised and recogniseable and also added Wendy Testaburger as an unnamed, non-speaking cameo.
 * The Beavis and Butt-Head episode '1-900-Beavis' has an early version of Dale Gribble appear as the husband/boyfriend of a phone sex worker. Wearing nothing but a pair of briefs.
 * The elephants from Disney's The Jungle Book actually all made their first appearances in the 1960 animated short Goliath II. The designs for the short's titular character and his father Goliath I were even recycled for those of Hathi Jr. and his father Colonel Hathi, as well as the scene where the elephants actually all pile up on top of one another.
 * The circus locomotive from Dumbo actually first appeared in the Disney animated short The Reluctant Dragon, where he is portrayed as pulling a passenger train (as opposed to a circus train) only to end up in a railway accident while attempting to jump a broken bridge during a thunderstorm. His Reluctant Dragon incarnation looked slightly different than the one in Dumbo: his drive rods are connected to the forward drive wheels, he was longer in appearance, and there was a bell on his roof. However in Dumbo, his drive rods are now connected to his hind drive wheels, he is now shorter and stockier in appearance, and his bell is nowhere to be seen, implying that he was actually overhauled during his repair between the two films.
 * Bambi also made his debut there, even though his official debut didn't even happen until the year after.
 * Laserbeak from Transformers Animated actually first appeared in the form of a toy that is packaged in the same blister pack as Animated Soundwave. Laserbeak himself won't appear in the cartoon until season 3.
 * Also, Shockwave in the Japanese opening.
 * Snips and Snails from My Little Pony Friendship Is Magic showed up as thieves in the Flash game Adventures in Ponyville on the Hub's website before their first appearance on the show. The game also showed Twilight as able to grant functional wings with magic, though they were a very different kind of wing (proper pegasus wings) than the ones she gave Rarity (butterfly wings made of gossamer and dew). Discover the Difference, another flash game on the Hub's website, provides glimpses at the beginning of the instrumental version of a Theme Tune Extended, as well as revealing scenes from "Owl's Well That Ends Well," "Party of One," and "The Best Night Ever."
 * The opening theme to the pilot episode of The Powerpuff Girls (which for some reason is drawn in a much cruder animation style than the rest of the series) has the Girls fight the Gangreen Gang long before their official debuts.
 * "Kid" from The Animatrix is a cross-medium example. He plays a significant role in the last two movies of The Matrix Trilogy but makes his first appearance in one of the shorts from the animated direct-to-DVD film.
 * Margo, the oldest of the three orphan girls from Despicable Me, wears a Lorax T-shirt; a movie version from the same producers premiered three years later.

Types 1 and 2:

 * In the two Iron Man movies, Captain America's shield can be seen on Tony Stark's worktable along with Thor's hammer. The Captain shows up in a block of ice for the alternate opening of The Incredible Hulk (2008) and got his own movie in 2011.
 * In the first film, Rhodey looks at the MK II armor, and says "Next time, baby!" He wears an upgraded version of that armor in the sequel.
 * Thor itself features a cameo by Hawkeye, who will be featured in The Avengers, as well as appearing in The Stinger.
 * While it has yet to come into play in the Marvel Cinematic Universe (and may never do so, dooming it to mere Easter Egg status), The Infinity Gauntlet is visible in Odin's trophy room/weapon vault. Considering appeared at the end of the Avengers film, the possibility of the Gauntlet becoming more important later on could be a little more likely now.