- DC Extended Universe
- The advertising campaign for Batman v Superman: Dawn of Justice heavily played up the fact that Jason Momoa and Gal Gadot would be making their debuts as Aquaman and Wonder Woman, respectively, and widely distributed publicity photos of them in costume. While viewers expected to see them, they probably didn't expect to see Ezra Miller in costume as The Flash, with actual dialogue and screen time. And though he's only seen in a still photograph, most people probably didn't expect to get a look at Chris Pine as Wonder Woman's old friend Steve Trevor. In Batman's nightmare vision, a squadron of Parademons attack Batman's forces, and Darkseid's Omega symbol can be seen burned into the ground; Mother Boxes also make a few appearances throughout the movie.
- Suicide Squad (2016) had several of these in its line-up. While characters like Deadshot, Harley Quinn, and Captain Boomerang are either team mainstays or popular characters in their own right, there are also characters like the Enchantress (not that one), El Diablo, and Slipknot, who are rather obscure and yet part of the main group. And related to the above movie, the Flash shows up, defeating Captain Boomerang. Even his co-star in the scene, Jai Courtney, was surprised, given the character wasn't on the shooting script.
- Among the characters in Justice League (2017), no one was expecting Commissioner Gordon (a vital element to Batman's lore, but not featured in Justice League stories due to the larger scale), Steppenwolf as the Big Bad, and Deathstroke (since the plot involves an Alien Invasion). Certainly nobody was expecting a member of the Green Lantern Corps appearing in the first fight against Steppenwolf years ago.
- Deadpool (2016) features appearances from Colossus, Angel Dust and Negasonic Teenage Warhead, all three of whom have close ties to the X-Men franchise, but none of whom are connected to Deadpool in the comics. And besides Colossus, the two ladies are unexpected for being rather obscure mutants - Warhead in particular was only included because the writers liked her codename. The Lawyer-Friendly Cameo by HYDRA agent Bob, made without name-dropping HYDRA, could also feel unexpected to viewers who thought Marvel Studios' ownership of the organization he works for would prevent him from appearing in a Fox movie. Deadpool sure sounds surprised to see him. In the same vein, although it's not a character, the final fight takes place on a crashed and disused Helicarrier from The Avengers (2012) and Captain America: The Winter Soldier, made most clear in the final shot.
- Kamen Rider:
- The crossover film Heisei Rider Vs Showa Rider Kamen Rider Wars Featuring Super Sentai has been dropping jaws with various returning characters. Shoutaro and Tsukasa? Awesome. Takumi? Wow, that's even better. Kusaka? But... how...? Keisuke Jin?! Holy... ''Freaking Takeshi Hongo?! This is gonna be the best movie ever!
- The film following that, Super Hero Taisen GP: Kamen Rider #3, introduces the titular Kamen Rider #3, who is in no way shape or form Kamen Rider V3 - instead, he was a Rider introduced in a story written by Shotaro Ishinomori back in 1972 and never had an appearance elsewhere.
- The 2017 Taisen film, Kamen Rider × Super Sentai: Chou Super Hero Taisen had a few, but the most notable were Shuichi Kitaoka, who hasn't been seen in a long time and is the second returning Ryuki character in 2017 after his Arch-Enemy Takeshi Asakura showed up in a Kamen Rider Ex-Aid special, and the Amazons Riders, who originate from an adult-focused spinoff and included Amazon Neo from the then-upcoming Season Two.
- Kamen Rider Heisei Generations: Dr. Pacman vs. Ex-Aid & Ghost with Legend Rider has, like the title reveals, the video game character Pac-Man. Before you ask, yes, THAT Pac-Man.
- Six members of the Green Bay Packers pop up at the a capella riff-off in Pitch Perfect 2, appearing as themselves.
- Scooby-Doo features Scrappy-Doo of all people as the Big Bad. He was kept hidden from marketing.
- Star Trek Into Darkness includes both Carol Marcus and Khan Noonien Singh as major supporting characters, but it introduces both of them under fake names ( "Carol Wallace" and "John Harrison", respectively) to hide their identities from savvy Trekkies who would already know them. Given that the film takes place in an Alternate Universe version of the Original Series era, most fans could deduce that both characters would be around somewhere, but the revelation of their identities is significant because it suddenly makes it clear that the film is really a loose What If? retelling of Star Trek II: The Wrath of Khan.
- Star Wars:
- Rogue One is a direct prequel to A New Hope, so it shouldn't come as a shock that Grand Moff Tarkin, Darth Vader, Princess Leia, her adoptive father Bail Organa (with the same actor as in the prequels!), and R2-D2 and C-3PO all make brief cameos. But absolutely no one expected Jyn Erso and Cassian Andor to run into Doctor Evazan and Ponda Baba on Jedha. It's a very brief moment, but it's likely to catch most Star Wars fans off guard.
- Solo has both a few obscure characters (Tag and Bink, Warwick Davis's character from The Phantom Menace) and Darth Maul as the true boss of Emilia Clarke's character. The last one is especially surprising even to fans who already knew Maul was still alive at this point in time, as not only did Solo not seem like the type of movie he'd be in, it didn't seem likely he'd be included in any new films due to potential Continuity Lockout with more casual Star Wars fans.
- The Rise of Skywalker: The first teaser ends with the distinctive Evil Laugh of Emperor Palpatine, who, in-universe, has been dead for decades. And then, at the Star Wars Celebration 2019 panel where the teaser was revealed, Ian McDiarmid came out on stage immediately afterwards and demanded the teaser be played again, suggesting that the character is more important to the movie than just being a simple Call-Back. This was further emphasized by said character's presence as an Evil Overlooker in the first proper poster.
- Super Sentai:
- Bio Hunter Silva, a villain introduced late into Choudenshi Bioman, completely faded into obscurity after the series ended its run. However, around 30 years later, he was added to the roster of a Super Sentai Legion of Doom during Kamen Rider X Super Sentai Superhero Taisen, and had something of a major role as well..
- In Kaizoku Sentai Gokaiger the Movie: The Flying Ghost Ship, one of the villains brought in is Baseball Mask, a simple Monster of the Week from Himitsu Sentai Goranger.
- Many fans were shocked when it was revealed that Kamen Rider X Super Sentai X Space Sheriff Superhero Taisen Z would also feature other Metal Heroes outside of the three Space Sheriffs.
- After Gokaiger Goseiger Super Sentai 199 Hero Great Battle, people thought there wouldn't be a crossover movie, because they just had it early on. Cue Kaizoku Sentai Gokaiger vs. Space Sheriff Gavan: The Movie, which brought back the Metal Hero franchise by bringing back Gavan!
- The later Super Sentai team up movies did this. Kaoru Shiba showed up for Tokumei Sentai Go Busters Vs Kaizoku Sentai Gokaiger The Movie, and the Kyoryu Sentai Zyuranger and Bakuryuu Sentai Abaranger teams show up in the crossover movie between Zyuden Sentai Kyoryuger and Tokumei Sentai Go Busters.
- Vernon suddenly shows up in a supporting role in Teenage Mutant Ninja Turtles (2014). He hasn't been seen or mentioned since the 80s version (and wasn't even included in 1990 movie where April likewise was a reporter) and thought long forgotten, so it was a surprise to longtime fans.
- Zombieland: The extended cameo of Bill Murray As Himself comes out of nowhere and was kept a secret until the release of the film.
Unexpected Character / Live-Action Films