The dream sequence and the idea of opening on a Show Within a Show version of Buzz Lightyear were scenes that had originally been planned from the first film.
Bo Peep was supposed to be part of the party sent to rescue Woody, but was kept behind as the as she's made of porcelain and fragile. In Toy Story 4 she's a deuteragonist who's right in the center of the action and adventure.
There is one scene deleted from the final cut where Timon refused to go help Simba and Pumbaa tries to encourage him. A storyboard version of it can be found on Youtube. The Lion King 1½ features a similar scene that relates to Timon's overall "dream home" subplot.
Concept art for "Warthog Rhapsody", which was replaced by "Hakuna Matata", uses a waterfall scene that looks like one used in 1 1/2. The tune for the song was reused for "Thats All I Need".
The Lion King was originally going to explain how Timon was kicked out of his colony during an earlier version of "Hakuna Matata", but it was cut for time. Timon's backstory was explored in far greater depth in the prequel/midquel, The Lion King 1½.
Finn McMissile was originally going to appear in the first Cars film as a character in a movie Lightning McQueen and Sally Carrera were watching in at a drive-in movie theater, but that scene was cut. He would be used as one of the central characters in the first sequel instead.
Fun and Fancy Free opens with Jiminy Cricket singing "I'm a Happy-Go-Lucky Fellow", which was originally written for him to sing in Pinocchio.
A few planned segments for Fantasia made it into some of the other package movies. One segment that was in fact fully animated and complete but omitted from the film (an egret dance scene to "Clair De Lune") was recycled for Make Mine Music!, but edited to the piece "Blue Bayou".
In the first movie, Jonathan was originally going to be a descendant of Dracula's enemy, Abraham Van Helsing, which would have given Drac even more reason to distrust him. This idea was reworked for the third movie, in which by Drac falls in love with Van Helsing's great-granddaughter.
The scene in the second movie where Drac discovers Mavis is pregnant was originally planned for the first movie as a flashback with Drac and his wife Martha.
In Finding Dory, the title character, Dory, has multiple flashbacks over the course of movie telling her backstory, which was originally intended for the first movie, as Marlin's backstory would've originally been told over the course of the movie in flashbacks.
An adaptational case occurs in Bambi II, which refits a scene from the novel not used in the first film where Bambi is almost caught by a hunter utilising a deer call. Since this was a midquel it actually regresses the timeline instead, Bambi is still a fawn and recognises the call as his mother's voice, while in the novel he was an adult who recognised it as Faline's.
An interesting variant for Spider-Man: Into the Spider-Verse. Peter B. Parker's story arc in this film reuses ideas from the unmade Spider-Man 4, specifically him divorcing Mary Jane. The original script for that movie had it come as a result of him cheating on her and ended with him abandoning her and their child; Sam Raimi felt that this made Peter come across as an unlikable jerk, contributing to the problems that ultimately got that film scrapped. Spider-Verse has the reason for the divorce be Peter simply undergoing a mid-life crisis that went From Bad to Worse after Aunt May died, causing him to act in an impulsive and self-destructive manner that ruined his marriage. It also ends on a much happier note, with him regaining his resolve and trying to patch things up with MJ.
An early cut scene from Frozen, back when Elsa was still a villain who froze Arendelle on purpose, is Anna saying "That's no blizzard—that's my sister!". The line "That's my sister!" was reused in Frozen II.
The Bohrok were the first character models made for Mask of Light, where they only landed a short cameo as frozen statues. The Bohrok body, sans head, was recycled into Vakama's small Fire Drones in the prequel, Legends of Metru Nui, where they appear in motion.
The obscure Lohrak beast was also modeled and a swarm of them were set to appear in a major deleted action scene in Legends of Metru Nui. In another case of reusing animation-ready models, a couple of them make a one second cameo in Web of Shadows.
Much of the original sword fight that would have been between Indy and the swordsman he shot instead made it into the sword fight at the end of Temple of Doom (where Indy tries the same thing, but his gun is missing).
The minecart chase was originally planned for Raiders (and even storyboarded) but had to be cut for pacing reasons.
Indy was originally to find the headpiece to the Staff of Ra in Shanghai, but the scene was cut before shooting. Elements of it (like Indy covering from gunfire behind a rolling gong) are in the opening of Temple.
The villain buying the pilots in Indy's plane, who parachute and leave him to crash, but he saves himself by using an inflatable raft to soften the impact. This was going to happen before Indy arrived in Egypt in Raiders.
Also the baby Tyrannosaurus killing a villain, the Compsognathus swarm killing another, the group hiding behind a waterfall and the adult rex being incapable of reaching them except with its tongue, and the raptors sneaking into a ship bound for the continent (though scenes with raptors aboard or on the mainland were cut, leaving the crew's deaths in the film unexplained). A baby Triceratops that was built for a Deleted Scene in the first film gets to appear in this sequel.
The appearance of the Stegosaurus herd in The Lost World is technically a role inversion. In the Jurassic Park novel, the main characters see a Triceratops herd and then find a sick Stegosaurus. The first movie combined both by making them find a sick Triceratops instead. In the second film, we recover the presence of Stegosaurus but in the role Triceratops had in the first novel. And we even get the main female character interacting with a baby Stegosaurus instead of the baby Triceratops mentioned above.
The book's aviary inspired a scripted pteranodon flock attack in the abandoned worker compound of TLW. CGI models and at least one animatronic were made, but the scene was too much of a challenge and was abandoned, the CGI models having just a cameo in the end. JP3's aviary is thus refitted from both the first film and its sequel. TLW was also originally intended to end with a shot of the pteranodons leaving the island; this was the ending shot of JP3.
Jurassic World refits the pteranodon attack once again, but closer to how it went in the TLW script (pteranodons attacking a large mass of people in the ground and a helicopter in the air at the same time, throwing a member of the crew out and impaling another through the front window, before making it crash). It also rescues a scene from the original book where Wu reminds Hammond that the park's dinosaurs cannot be considered real dinosaurs because of how much foreign DNA was inserted in them to complete the sequence, but this time it is an older Wu saying it to Hammond's replacement, Masrani.
Other previously discarded elements in Jurassic World include a raptor being killed by a rocket launcher (from the Jurassic Park novel), a motorbike chase with raptors (though in the movie the raptors and the bikers are on the same team), the I. rex's ability to cammouflage itself (which was a natural ability of the Carnotaurus in the The Lost World novel), the appearance of Apatosaurus (also from the first book, changed to Brachiosaurus in the first film because it was taller), and baby Triceratops rides as a children's attraction (Lex was going to ride a baby Triceratops in the first film but it was cut for pacing).
Cloud City in Empire was based on concept art for the Imperial capital city. A later draft repurposed the floating city as a Penal Colony, and the finished film moved those scenes onto the Death Star itself.
A ground battle at the Rebel base on Yavin was later adapted to the Battle of Endor (a similar forested planetoid) in Return of the Jedi. And while Jedi turned the Wookiee planet into the Ewok one, Revenge of the Sith actually went to Wookiee homeworld Kashyyyk.
In the original script, Tatooine would have been named Utapau. When The Phantom Menace rolled around, Lucas tried to use the name with the planet that ultimately became Naboo. He was finally able to use the name in Revenge of the Sith for the planet where Obi-Wan Kenobi fights General Grevious.
The TIE Bombers featured prominently during the asteroid scenes were based on concept drawings for an Imperial boarding craft that was supposed to be shown boarding Princess Leia's ship at the beginning of A New Hope. Rogue One finally featured the TIE Bomber boarding craft.
The planet which would become Coruscant was first planned for Jedi, but realizing a planetwide city onscreen was technically impossible at the time, a second Death Star was used instead. A shot of Coruscant was later added to the Special Edition.
In early drafts of Jedi the final showdown with the Emperor was supposed to take place on a volcanic lava-covered planet called Had Abbadon. The lava planet idea was revisited as Mustafar in Sith, while the name "Had Abbadon" made it into the Star Wars: Legacy comic as a planet name.
Legendary designer Ralph McQuarrie came up with designs for a lava-planet castle that Darth Vader lived in as far back as Empire Strikes Back before it finally appeared in Rogue One.
George Lucas wanted to include an amphibian frog-like alien among the main cast as far as the original A New Hope script, where Han Solo was it. This became a reality with Jar Jar Binks in The Phantom Menace.note Made evident by the script saying Jar Jar has a "frog face", though his final design looks not much like one due to him incorporating a deliberate likeness to Goofy. Jar Jar also inherited his "life debt" to Qui-Gon from Chewbacca's life debt to Han, which was mentioned in the A New Hope scripts but not in the final film (but is referenced in the expanded universe).
Vito's backstory in The Godfather Part II is taken from scenes in the original novel which were left out of the first film.
The bathroom set in X2: X-Men United was originally built for a flashback scene Cyclops discovering his powers, that was left before being shot. A scene similar to what they'd intended turns up in X-Men Origins: Wolverine, and the first time Cyclops uses his powers in X-Men: Apocalypse is in a bathroom.
The entire adventure in the Old Forest with Tom Bombadil got Adapted Out from The Fellowship of the Ring. However, part of it (specifically, the hobbits getting attacked by a hostile tree) got worked into the Extended Edition of The Two Towers, taking place in Fangorn Forest with Treebeard playing Bombadil's role.
The prelude to The Return of the King featuring Sméagol was originally intended to be a flashback during the Dead Marshes scene in The Two Towers where Frodo voices Gollum's real name to him, sparking old memories. In the book, the flashback takes place even earlier, in the first book: Gandalf tells it to Frodo still in Hobbiton when telling him about the true nature of the Ring.
The scenes where Théoden and co. go to Isengard were originally planned for the end of The Two Towers, but were moved to the beginning of The Return of the King due to Ending Fatigue. The talk with Saruman even ended up cut from the theatrical cut as it was anticlimactic, but the Extended Edition restored it as it was meant for watching the trilogy back to back.
This comes up again with The Hobbit (especially in the Extended Editions), which recycles a number of scenes or moments from the Lord of the Rings books that couldn't make it into the movies. This kinda makes sense, considering that the Hobbit book is far too short to fill a trilogy.
Inverted in Superman: The Movie, where the "spin the Earth backwards-time travel" ending in the first film was actually planned to be used at the end of the second, but Donner added it to the first film to create a more memorable climax. Spinning the Earth backward was used again in the Richard Donner cut of Superman II.
Zod and co. were originally meant to come to Earth in the first movie but were saved for the sequel because it would make the movie too long.
An early draft had the Enterprise performing a saucer separation because of a Klingon attack damaging the engineering hull. A saucer separation later features prominently in Star Trek: Generations, where the Enterprise-D is badly damaged from an attack by a Klingon Bird-of-Prey and conducts a saucer separation. In turn, this specific sequence in Generations of the Enterprise-D separating its saucer section, the drive section exploding and the saucer section crash-landing on a planet's surface was originally conceived as a possible cliffhanger ending for a season finale of Star Trek: The Next Generation.note Behind the scenes this would have also been an opportunity to redesign the ship's drive section, as they found the Enterprise-D's top-heavy design difficult to photograph. Ultimately it was saved for the movie instead.
In Part II, as Marty McFly tries to sneak by the car with his other self and Lorraine in the first film, he hears Lorraine say "When I have kids, I'm going to let them do anything they want. Anything at all!", to which his other self says "I'd like to have that in writing...", which was originally part of that scene before being cut for pacing.
In the first film, the producers considered using "Papa Loves Mambo" by Perry Como when Marty arrives in the 1955 Hill Valley, before deciding on "Mister Sandman" by The Four Aces, thereby making it the "Mister Sandman" Sequence. In Part II, the song is used as Biff drives to the Enchantment Under The Sea dance.
It's widely known that the time machine was originally conceived as a chamber (specifically a refrigerator), and in order to travel back to 1985, Doc and Marty would've sneaked into a nuclear testing site in the desert to get the necessary 1.21 gigawatts of electricity. In Back to the Future Part III, the 1955 Doc sends Marty to 1885 at a drive-in theater in the desert.
The death of the teacher and the factory finale in Child's Play 2 were both intended to be featured in the original.
The opening scene in Child's Play 3 was originally how Child's Play 2 would have ended (And, in fact, a different version of it is used in some TV versions). It was also how Child's Play was going to end back when the factory was the intended finale
The evidence locker scene in Bride of Chucky was going to be the opening of Child's Play 2.
The electrocution of Tiffany in Bride of Chucky was how the babysitter died in an earlier draft of the first film's script.
The ending of Curse of Chucky with the court case and Chucky being among the evidence and Fioana being declared legally insane was intended for the beginning of Child's Play 2 with Karen Barclay's character
Initially, there was supposed to be a shot in Curse of Chucky that revealed that Andy owned a gun store, illustrating just how ready he was for Chucky's return.
The scene in Ghostbusters II where a woman gets attacked by her fur coat coming to life after she walks through a slime puddle was originally written for the first film. Also, the part where Ray knocks out the whole city's power is a refit from the original screenplay: Egon's prototype Proton Pack, which needed to be plugged into a heavy-duty outlet (for safety reasons, he hadn't fitted the particle accelerator yet). Plug in, switch on, and...the power went back through and melted the cable, reached the outlet, and knocked out all of New York's power.
Once Upon a Time in Mexico contains several scenes that were leftover from El Mariachi and Desperado. The hotel escape was originally intended for the latter, and the escape from the compound (while guarded in a jail cell) was included in the original script for the former.
The latter portion of the scene featuring Harris and Proctor at the Blue Oyster Bar in Police Academy 4: Citizens on Patrol was originally written for Art Metrano and Lance Kinsey in Police Academy 3: Back in Training. However, the scene was removed from the final draft for the third film, and used in the fourth film instead, with Mauser's role being reassigned to Harris.
Early drafts of Sex and the City: The Movie featured a subplot about Charlotte's fear that her husband was having an affair with their young, braless nanny. The idea was removed in subsequent script revisions, but ended up being used in the sequel, where the nanny in question was played by Alice Eve.
The scene in Blade: Trinity where vampires keep humans in giant blood bags to feed on was an idea meant for the first film.
Blade Runner had a storyboarded, but unused, opening that involved Deckard shooting a Replicant on a farm, before tearing open his head to reveal its robot parts. This was eventually reworked and used as the opening of the sequel, Blade Runner 2049.
James Gunn originally intended to have Adam Warlock join the team in Guardians of the Galaxy Vol. 2, but had had to remove him from the script due to concerns about there already being too many characters. It's since been confirmed that Warlock will appear in the third Guardians of the Galaxy movie.
Thor: The Dark World was originally going to feature an appearance from Valkyrie, but the idea ended up being scrapped. Valkyrie would later be used as a major character in Thor: Ragnarok. Hela was also planned to be the villain in The Dark World at one point, but was likewise reused for Ragnarok.
Director Jon Watts wanted to use Nick Fury as Peter Parker's mentor figure in Spider-Man: Homecoming but Marvel Studios had him use Tony Stark instead due to the existing relationship between the two characters. Fury would later be Parker's mentor throughout the sequel, Spider-Man: Far From Home.
The opening scene of Avengers: Endgame with the Barton family was originally planned for Avengers: Infinity War, but then Joe Russo decided to make it this film's first scene. The writers all felt that Hawkeye's character became more dramatically impactful after the snap whereas his arc in IW would have repeated beats from Captain America: Civil War, i.e. a hero coming out of a 10-Minute Retirement.
An early draft of Shock Treatment had Brad turning gay and leaving Janet then Janet giving birth to Frank's son. These were planned to be used in later sequels like Revenge of the Old Queen and Rocky Horror 2000 that never got made.
The fight in the glass factory in Moonraker was originally meant for The Spy Who Loved Me, where it was a fight in a museum.
Many production and story ideas and elements not used in Moonraker ended up being utilized for Octopussy. These included the knife throwing twins and the Acrostar Bede jet sequence. The backgammon game was originally intended to take place in Max Kalba's club in The Spy Who Loved Me.
The assassination via poisoned butterfly and leap from the Eiffel Tower from A View to a Kill appeared in early drafts for Moonraker.
Stamper from Tomorrow Never Dies was originally going to be unable to feel pain. The idea was reused for Renard in The World is Not Enough.
The scene in Spectre where Bond steals an un-equiped Aston Martin and escapes via ejector seat is a leftover from the unmade Property of a Lady (Timothy Dalton's planned third film before the franchise entered Development Hell in the early 1990s).
According to Word of God, in Godzilla (1998) there were going to be other kaiju, but they got held back to appear in the sequel. Perhaps if they had put them in the movie there would actually have been a sequel.
Early drafts of Teenage Mutant Ninja Turtles (2014) featured Casey Jones, Beebop and Rocksteady, but all three characters ended up being written out. They appeared in the sequel.
The Fly (1986) originally had a short scene in which, the morning after Seth's fateful teleportation, Veronica videotapes an interview with him about what the experience felt like; this was filmed but cut for pacing reasons. In The Fly II, their Spin-Offspring Martin watches the interview as he ponders whether to continue his father's work. The scene is edited to avoid showing Veronica as Geena Davis did not come back for this film due to her character suffering Sudden Sequel Death Syndrome in the opening scene; her offscreen questioning was rerecorded by Saffron Henderson, who took her place. The original version of the scene appears as a bonus feature on non-Vanilla Edition releases of the first film.