People in Real Life are unique, irreplaceable, with their own specific background and personality.
Not so in fiction. Some characters are better known as symbols than as people. Consequently, as long as you keep the basic elements of a character (their essence) you can have infinite variations of the same character. Without those elements, you would have a completely different character rather than a new version.
Any character can undergo some variations Depending on the Writer. But not every character can have major reinterpretations and remain the same character.
For example take Batman. He has numerous different interpretations. Some are campy, some are realistic but gritty, some are darker, cartoony etc. But all share the basic elements of a man named Bruce Wayne who dons a bat costume and fights crime. If we saw another character named Batman who stayed at home and argued eloquently on the Internet, we'd have a totally different character, despite the name.
On the other hand Jack Sparrow from Pirates of the Caribbean isn't as interpretative. You can't just take any drunk pirate and call him "Jack Sparrow". Anyone who tries to emulate or parody him, would need to keep Johnny Depp's mold intact. This character's specific personal appearance, clothes, mannerisms, and manner of speech would need to be kept the same (or exaggerated in case of parody). Disney even admitted that without Johnny Depp the franchise would be "dead and buried". His characterization may change slightly Depending on the Writer, but there isn't really much room for variation.
Contrast Captain Ersatz, where a variation of an Interpretative Character is introduced as a new character, and Expy, where a new character is designed around the defining tropes of another non - Interpretative Character.
- The aforementioned Batman. His interpretations range from the cartoony (Batman: The Brave and the Bold) to the farcical (the 1960s series) to the dark and artistic (the 1989 movie) to the gritty (The Dark Knight).
- Bruce Wayne is Rich. He's been a clownish Rich Idiot with No Day Job and a hardworking Honest Corporate Executive; as long as the Rich bit is in there, nobody seems to care about the details.
- Classic Batman stories depict Batman as a mask for Bruce Wayne, while modern versions of the character depict him the other way around.
- Superman: He's Powerful and The Good Guy (tm). But how powerful is he? Is he a patriotic character, or does he transcend nationalism? Is he mostly alien, or mostly human?
- Taken Up to Eleven with Superboy. In Young Justice Superman was very disturbed by his existence. But in the Smallville version Superman accepted him with open arms even after he became evil.
- Another interpretative aspect is the question of whether Superman is his true self and Clark Kent the facade, or vice-versa. Classic iterations go with the former, while most modern iterations go with the latter.
- Wonder Woman has had many interpretations, ranging from a patriotic freedom fighter (Golden Age), a Lady of War on par with Xena, Ambiguously Bi, a very lawful but less assertive hero who defers to her male teammates (in the Silver Age), a Badass Normal super spy, a Straw Feminist, or a calm and mature authority figure (most modern incarnations tend to be a mix of this and Lady of War). It's been pointed out by one writer that one of the reasons Diana has so many interpretations is that every writer and artist has their own idea of the perfect woman.
- On the villainous side, The Joker. He's an enemy of Batman, but is he a common thug, a vandal who fancies himself an artist, a nihilistic anarchist out to prove everyone's as bad as him inside, a depraved Serial Killer who targets Batman's friends or what-have-you? He kills his victims with a smile, but does he use a fatal injection that tightens their face muscles, curable laughing gas, or does he just slit their faces into a Glasgow Grin? And just what is his origin anyway?
- It's generally accepted that there are three phases of Lex Luthor. 1) a world-reviled criminal mastermind and war profiteer. 2) a Mad Scientist. 3) an absurdly rich Corrupt Corporate Executive with a certain level of good publicity. The latter has arguably been the most popular portrayal for the last three or four decades, but as long as you make him bald and Superman's enemy, he's likely to fall into one of those three categories.
- The Incredible Hulk is all over this: is the Hulk an aspect of Banner's psyche brought to life? A completely separate individual? A psychological child (emotionally innocent but easily angered)? Really kind of dumb, of at least average intelligence using Hulk Speak as a verbal tic, or using it to deliberately downplay his intelligence? All of these have been used. Adding to the fun is the fact that the Hulk sometimes manifests as a Genius Bruiser with a ponytail or a grey-skinned morally flexible thug, and the same or similar questions play out.
- Godzilla over the years has been portrayed as a villain hell-bent on destroying all of humanity, an Anti-Hero force of nature, and as a heroic Jerk with a Heart of Gold.
- James Bond. At heart, he's The Casanova super spy who drops a good Bond One-Liner. Anything else is up for interpretation.
- It doesn't help that some interpret the inconsistent casting of the character as actually being different characters entirely - all sharing the codename "James Bond".
- Zorro has been variously portrayed as lighthearted, vengeful, political, campy, or romanticized, depending on the filmmaker and era.
- SpiderMan has been interpreted very differently across the three recent film adaptations. Tobey Maguire portrays him as meek, serious and a bit of an Extreme Doormat. Andrew Garfield's take is more of a snarky loner who starts of as much more of an Anti-Hero. Tom Holland plays up his youth and inexperience, coming across as awkward and a Motor Mouth (this version is widely considered the closest to the comics).
- Alice in Wonderland : At her core, she is the Only Sane Man; an Every Girl in a Cloud Cuckoo Land. But is she an innocent yet somewhat typical little girl among fuzzies, a mad girl exploring the dark recesses of her own psyche, or an unconventional woman who's actually stumbled into another plane?
- The Wizard of Oz has thousands of different interpretations for all the characters. They all have their cores; Dorothy wants to get back to normalcy, the Scarecrow wants a brain, the Tin Man wants a heart, and the Cowardly Lion wants courage. There is a Good Witch and a Wicked Witch who approaches Dorothy when she arrives in Munchkinland. The Wizard of Oz is a scary illusionist and big fat liar. The things they do and how they accomplish them vary quite a bit with each interpretation.
- Sherlock Holmes. His interpretations on screen have ranged from Basil Rathbone's mildly eccentric English gentleman, Jeremy Brett's bipolar genius, Robert Downey, Jr.'s intellectual Badass Bookworm and Benedict Cumberbatch's borderline autistic savant; all of which can be totally justified from the original texts.
- For that matter, Dr. Watson. Just respectively you've got Nigel Bruce's bumbling comic relief, Burke/Hardwicke's accomplished surgeon, Jude Law's long-suffering Deadpan Snarker, and Martin Freeman's out-of-his-depth closet adrenaline junkie. Again, any of these could be fairly gleaned from reading the books.
- Lampshaded in Paul Cornell's short story "The Deer Stalker", in which Holmes and Watson are hunted by a sinister force that's "decontextualizing" people, stripping them down to their essential characteristics and causing everything else about them to constantly fluctuate. Previous victims include Lee Harvey Oswald, Dracula, Calamity Jane, and Alice.
- Charlie and the Chocolate Factory has Willy Wonka: At his core, he is a brilliant, reclusive, lively Mad Scientist of candymaking who has highly Skewed Priorities when it comes to the fates of those who enter his world and don't heed his warnings, owing to his unique way of thinking, and a Trickster Mentor seeking a successor. Adaptations and their actors have built on this in a variety of ways: Gene Wilder plays up the Trickster aspect to the hilt, even deliberately scaring the Golden Ticket tour group for fun. Johnny Depp plays him as a Manchild whose years of isolation from the rest of the world result in him having trouble just speaking to, much less interacting with, his visitors in ways they would regard as "normal". In the 2002 audiobook version, Eric Idle plays up the character's boundless energy, which makes him something of a mad optimist even in the darkest moments. In the 2013 stage musical, Douglas Hodge plays him as a Mad Artist / Mad Scientist hybrid with a Sugar-and-Ice Personality: He's usually frosty towards the tour group, focusing on the business at hand rather than getting to know them, and to the bad seeds he shows stealthy contempt and, when they meet potentially deadly fates, truly blithe indifference. Yet he's sensitive to creativity and beauty, capable of showing great kindness and warmth to those who can appreciate and understand his way of thinking.
- Parodied in the Kim Newman short story "Coastal City", which pokes fun at superhero comic tropes. The Commissioner Gordon is uncomfortably aware that he can vary between being useless, a trusted ally, or a J. Jonah Jameson-esque Inspector Javert depending on which hero he's dealing with at the time. He's also notes that the woman working in his office looks like Sharon Stone and is on the force, but he swears she used to look like Ginger Rogers and just be his secretary.
- The Doctor themself on Doctor Who. At their core they are an eccentric but heroic elderly figure with a time machine. However, every Doctor will be different from their other incarnations. Tom Baker, who played the Fourth Doctor, often says that the premise is so open to interpretation that no-one has ever 'failed' as the Doctor and no-one ever can.
Sycorax Leader: Who exactly are you?10th Doctor: Well, that's the question.Sycorax Leader: I demand to know who you are!10th Doctor: (mock-imitation of Sycorax Leader's voice) I DON'T KNOOOW !! (back to regular voice) See, that's the thing. I'm the Doctor, but beyond that, I.. I just don't know. I literally do not know who I am. It's all untested. Am I funny? Am I sarcastic? Sexy? [winks at Rose, who looks away, embarrassed but smiling] Right old misery? Life and soul? Right-handed? Left-handed? A gambler? A fighter? A coward? A traitor or a liar? A nervous wreck? I mean, judging by the evidence, I've certainly got a gob.
- The various reincarnations of Link and Zelda in The Legend of Zelda series. Though this has an in-universe justification for the various interpretations.
- Carmen Sandiego. She's the red-coated nemesis of the ACME Detective Agency and the ringleader of V.I.L.E. Since the early '90s, her Back Story always involves her being a former ACME detective. Within those parameters, pretty much anything can be changed, including how much (if any) goodness is left in her.
- Most of the controllable characters in Kentucky Route Zero such as Conway, Shannon, and Lula are left to have their details filled in by dialogue choices.
- Mario. Given the sheer longevity of the series and the amount of creative teams in charge of each game, his personality and traits are subject to change depending on whatever circumstances he finds himself in. Luigi, on the other hand, developed a more solid, definite personality as the series went on.
- Every one of the standard Final Fantasy recurring characters - mascots like Chocobos and Moogles, summoned monsters like Shiva, Ifrit and Bahamut, and monsters like Mandragora and Cactuar get reinterpreted along the aesthetic of every entry they appear in. This does lead to some weird effects, sometimes - Final Fantasy XV contains both a 'serious' interpretation of Ultros (Kingsglaive: Final Fantasy XV) and a goofy version in line with his usual interpretation (A King's Tale: Final Fantasy XV).
- Jenny Everywhere, a character who was made for the sole purpose of being inserted into any continuity through any interpretation.
- Newgrounds' Iconic Series Mascot, Pico, first appeared in five flashes by Tom Fulp, and ever since then has been kept alive by the flashes of several Newgrounders who took him in almost any direction under the sun. At his base, he is a badass Fiery Redhead juvenile weapons expert in a green long-sleeved shirt. Everything beyond that is up for grabs from how old he is to his relationship with Nene and Darnell.
- Nene and Darnell tend to variate with Pico as well. Nene at base is an Asian girl in an overall dress with a long-sleeve shirt with matching shoes and a headband, all of which are pink. From that point, she could either be a caring love-interest/girlfriend to Pico or ready and willing to coldly slit his throat when the situation calls for it. Her Subverted Innocence, namely her sexual and suicidal tendencies, are usually mainstays, but they also tend to fluctuate. Her Vague Age and Troubling Unchildlike Behavior tend to be the same as Pico. Darnell is more stably characterized, being black with a slicked 'do, wearing a purple-and-yellow long-sleeved shirt and blue jeans, and being a pyromaniac who plays the Littlest Cancer Patient card (usually a lie) to bolster his chances for class president. Likewise, he also carries Pico's Vague Age and Troubling Unchildlike Behavior.
- The Slender Man is tall, slender, wears a dark business suit, and is generally used for the purpose of horror. Anything else is fair game. Even his most identifying feature (his facelessness) varies between "doesn't exist" and "just doesn't show up on camera."
- Mickey Mouse. Seeing as how there isn't really a "definitive" story for him, like Disney's fairy tale characters, he's very much this. Throughout his history, he's been portrayed as a Screwy Squirrel in the early days, a Vanilla Protagonist Nice Guy, a badass Big Good, and even a Corrupt Corporate Executive in parodies.
- My Little Pony is a big example. Take Rainbow Dash for instance; Rainbow Dash at her core is a female pony with a rainbow colored mane. However, her G3 incarnation is a girly girl fashionista who only cares about clothes. Rainbow Dash from My Little Pony: Friendship Is Magic on the opposite is an athletic girl who is well known for her awesome physical feats and couldn't care less about fashion. The reason why My Little Pony characters are such good examples of interpretative characters is because they are all, in the end, defined only by their name, color scheme and hip-symbol (at least in FiM, it's called a cutie mark). That is why a character like Rainbow Dash can have one personality in one version and a completely different personality in another version while these radically different interpretations are still considered variations of the same character.
- Transformers is the same. And then, you have to differentiate between "new version of character X" and "new character with a name we've heard before slapped on it." The Powers That Be aren't too particular about how smaller names are used (Starscream's never not gonna be The Starscream, but minor characters may never get the same portrayal twice. And there've been so many that the writers may truly be unaware that waaaaaay back in 1987 there was a guy in one issue in one comic by that name.) A couple big names:
- Megatron. For any kind of villain you've ever seen, there's a Megatron for that. He's been a brute, a brilliant manipulator and chessmaster, a one-bot army and far-thinking master planner, an energy vampire, and an extremely 80s cartoon villain with a high-pitched voice and schemes like "I know how we can get more energy! Let's build this giant cannon to knock the Moon out of orbit, build a device to control the tides in the Moon's absence, and then use all that power to flood a canyon that contains a hydroelectric generator that we built." He's also tried Omnicidal Maniac on for size once (in Transformers Cybertron, his true plan proves to be to use the black hole to eradicate the whole universe, then rebuild it in his image). He is always The Determinator, though.
- Starscream is always going to try and screw Megatron over, but why? Does he just want power for himself? Does he want the best for the Decepticons and honestly believe it's not Megs? Is he right about that? Was he loyal until Megs screwed him? Does he stay with the 'cons, or does he become a third faction? When he does get some power, is he any good at using it?
- On the good guys' side, Optimus. He's similar to the Batman example. He'll always be The Hero, always the leader, always serious but with the occasional sign of a sense of humor and A Father to His Men. The exact flavor depends on the tone of the series, though. In the film series he's The Berserker in battle, and in Beast Wars and Animated, he's the leader of the team but not the Autobots altogether. (A big brother to his men?) In a darker series, he won't hesitate to kill; in a lighter one, he's always willing to forgive. Sometimes he's willing to say I Did What I Had to Do, and sometimes it's "showing mercy even if it's probably gonna bite us down the road is what makes us better than the 'cons."
- Ironhide's been an old and Southern minivan, stealthy and Southern truck, a young and not Southern truck, a truck who really loves his guns (fitting an American Deep South stereotype despite not having the accent), and most recently young, Southern, and... a vehicle that's trying really hard not to look like a repaint of Ratchet's pre-Earth alien-ified ambulance mode who probably would have traded that alt-mode in a truck.
- For a minor-name case that may not be intended as a new version of an existing character, there's Blackout. We've got Demolishor's ground-vehicle Robot Buddy in Transformers Armada, the toy name of an unnamed Bruticus Maximus component in Transformers Energon, a bird Terrorcon drone in the show proper, and a helicopter-bot who all but wiped out a whole military base in the first live movie. Animated Blackout is basically movie Blackout in the show's animation style, though. Movie Blackout may be a reference to fellow helicopter Bruticus component Blackout, but that's a stretch - Energon combiners are single characters who split, not teams who combine. Energon Bruticus' leg having a name is obscure trivia.
- Rampage: big cat, Hannibal Lecter in the form of a giant crab, or a construction vehicle? Like Blackout, being a 'con is all the uses of the name have in common.
- Scorponok is borderline. As a Decepticon scorpion, he feels more like a recurring character than an oft-reused name. However, the name "Scorponok" pretty much has to be used for a scorpion, and a scorpion pretty much has to be bad. Beyond this, nothing is the same twice - he's been a non-sentient, crazy enormous base-turned-robot used by an alien warlord, a leader of the Decepticons in Megatron's absence, an unremarkable button-man, and a conflicted Anti-Villain.
- Wheeljack has his share of changes per continuity. In G1 he's a Gadgeteer Genius whose inventions have a varying degree of success. In Transformers Armada, he is an Autobot turncoat who sides with the Decepticons. In Transformers Prime he's a member of the Wreckers, a badass One Bot Army who can take on multiple 'cons all at once.
- Ultra Magnus tends to be a high-ranking, powerful soldier connected to Optimus Prime in some way, sometimes being his brother. His characterization primarily comes from the rank of Supreme Autobot Leader somehow. In G1 he feared and avoided such responsibility despite being well cut out for it, in Transformers: Robots in Disguise he was jealous of Prime for being chosen to be leader, and in Animated he already was a responsible leader who saw potential in the young rookie known as Optimus Prime.
- Sentinel Prime is far more vague, not even having a concrete basic visual design unlike most of the above, but somehow relates to being Optimus Prime's superior somehow. In G1 he doesn't have much of a characterization beyond dying and passing the Autobot Matrix of Leadership to Optimus, but was brought back for Animated as a complete and utter Jerkass who keeps rubbing it in Optimus' face that he is in the Elite Guard whereas Optimus is just a maintenance bot despite the fact that Optimus sacrificed his chances for the Elite Guard for him. note In Transformers: Dark of the Moon however, he is Optimus' highly respected predecessor and mentor whom he brought Back from the Dead in hopes of ending the war only to find out that he is a Well-Intentioned Extremist with A God Am I tendencies who allied with Megatron long ago in a plan to send Cybertron to Earth and restore it using Earth's resources and Puny Earthlings. Notably, the two recent depictions of Sentinel Prime tend to play Actor Allusion/Ink-Suit Actor. Animated Sentinel was voiced by Townsend Coleman and is basically The Tick in Transformer form, whereas DOTM Sentinel is modeled after his voice actor Leonard Nimoy, and even shares a line with Spock.
- The Scooby-Doo gang to varying degrees. As the straight men of the group in the original incarnation, Daphne and Fred have been subject to the most revision, with Fred rocketing between reliable leader and blustering goofball and Daphne as danger-prone damsel, quick-witted Action Girl and kooky Cloud Cuckoolander. As more specific characters, Velma, Shaggy and Scooby have experienced far less variation; Velma remained a cheerful, easygoing genius until Scooby-Doo! Mystery Incorporated turned her into a Daria-esque snarker with a sweet spot for Shaggy.
- G.I. Joe, being by the same company as Transformers and often sharing its creative staff, handle characters the same way. Some characters have nothing in common beside sharing a name for the sake of trademark retention (so Rampage, the rough vehicle driver from G.I. Joe A Real American Hero has nothing to do with Rampage, the unhinged arm dealer from G.I. Joe Extreme), some characters had more or less consistent portrayals among the various continuities (every incarnation of Destro is a mask-wearing Scottish arm dealer, every incarnation of Roadblock is a Scary Black Man) and others are in-between, having the basic of their design and role nailed down but wildly different backgrounds and portrayals.
- The biggest example of the later is Cobra Commander. Over the years, Cobra Commander has been portrayed as an used car salesman who went insane after losing everything, a shrill goofball eventually revealed to be a spy sent by an ancient underground civilization, a ruthless cyborg warlord, a bloodthirsty maniac playing dumb, and more.
- The Teenage Mutant Ninja Turtles as a group tend to have different characterizations depending on adaptation and medium; they're goofy, wisecracking, catchphrase-spouting do-gooders in the 1980s cartoon, vengeful ninja warriors in the original Eastman and Laird comics, and an amalgamation of both in most modern adaptations. Leonardo and Raphael tend to change the most, with Leonardo written as either a straitlaced, adorkable everyman or a calm and stoic fighter who takes his duties as a leader and a ninja very seriously, and Raphael as a Deadpan Snarker with a laid back personality, a hotheaded grump, or a violent, brooding Anti-Hero. Michelangelo and Donatello generally stay the same, Mikey being the outgoing "party dude" and Donatello being the nerdy inventor, though Michelangelo's depiction as a party dude generally depends on what's considered cool and hip at the time. Mikey from the 80s and 2003 cartoons is a surfer dude, and Mikey from the 2012 cartoon and 2014 film generally acts like a millennial.