On The 100, Octavia desperately tries to do this, embracing Grounder ways and rejecting most of her ties to the Sky People, but she can never quite gain acceptance among the Grounders. Her lover, Lincoln, is a Grounder, but the rest of his people accuse him of Going Native with the Sky People, even though Lincoln's acceptance among the Sky People is only slightly better than Octavia's among the Grounders.
In The Americans, Phillip and Elizabeth Jennings are Russian spies who were sent to America back in the 60's. After 20 years in the States, Phillip has increasingly embraced American culture, creating a rift with Elizabeth, who has remained largely loyal to the Soviet Union.
The first Kosh seems to have gone native with humanoids, in a sense. To the point of helping to assassinate his successor to prevent him from warning the other Vorlons about Sheridan's plans.
Delenn was accused of doing this by other Minbari and in fact she had, biologically speaking. Culturally she remained a Minbari. Racism aside it is perhaps a legitimate fear that a diplomat will do this if in contact to long and so the Grey Council may have not been totally irrational.
Sinclair fits in so well as Minbari Ambassador that this seems to be the trope. However, it's the other way around, Minbari culture is based around his role as Valen.
Accusations of going native from extremists are common in the series. The xenophobic Clark regime tried to dismiss Babylon 5's opposition to them by claiming Sheridan had succumbed to a made-up condition they called "Minbari War Syndrome".
During his assignment to Minbar, Vir goes Full Native. Much to Londo's chagrin. The extent of his Native turn eventually causes some interesting story.
The previous Centauri ambassador to Minbar also went native, which is why the Centauri took so long to send someone again. According to JMS, he's in retreat somewhere, meditating and trying to grow a head bone.
The Book of Boba Fett: After surviving the Sarlacc pit, Boba Fett is stripped from his armor by Jawas and enslaved by a Tusken raiders tribe. One day he saves the life of a Tusken child by killing a sand monster, and the tribe starts integrating him. He helps them getting rid of a heavily armed Pyke Syndicate train crossing their territory, and in turn they teach him their gaderffii staff-based martial art, dress him like them and have him build his own staff (he had to go through a ritualisticMushroom Samba first). It doesn't end well for the tribe as they're wiped out by the Pyke Syndicate, but the experience does a lot to end Boba's lone wolf attitude, driving him to form his own crime syndicate based on mutual loyalty.
Michael jokingly accuses the security chief for the Pakistani consulate of going native after finding him in an Indian restaurant. May be a subversion, as the cultures of India and Pakistan are almost indistinguishable.
Waseem: Oh, I like the chicken tikka.
Almost fully happens to Michael during the final season, which saw him having to live the life of a disavowed and desolate former agent in order to attract the attention of the terrorist group he needed to get in with. By the final episodes, even after making contact with his friends again, he's spent so much time with no back up, no resources, pressure from his handlers who only want top-tier results, and the largely sympathetic nature of the terrorist that got so many on his side in the first place, Michael is only moments away from embracing the other side before he is brought to his senses.
The Doctor has, over the course of their very long life, grown very fond of Earth. They still love to travel, and are a little too alien to really be considered a "native", but the Doctor loves everything about our culture, clothes, food and people. Particularly conspicuous in the Classic Series, when they frequently interacted with the Time Lords, throwing into sharp relief how utterly... well... alien their human-esque appearance and behaviour seemed to other members of their own species. The Tenth Doctor was probably the biggest example of this, almost to the point of Become a Real Boy.
In "Boom Town", a stranded alien has been covertly living as a Welsh politician, and, even as she plots to blow up the entire Earth to facilitate her escape, grumbles that the London-based government wouldn't notice if Wales slid into the sea. She then immediately labels the moment as an example of this trope.
Sully in Dr. Quinn, Medicine Woman often seems to relate more to his Native American friends than the white folks in town.
In the episode "Another Woman", a white woman is rescued following a raid on a Native American camp. It turns out she was raised by the tribe after having been abducted at such a young age that she barely remembers her old life or how to speak English.
In Farscape, the Peacekeepers are so paranoid about this happening to their troops that they consider anyone who even speaks to an alien without explicit authorization to have become “irreversibly contaminated”note The commanding officer who ordered that designation for so little was noted to be insane and twisting the rules to the point that the officer in question is later told she could have come back to the fold after he was relieved of command if she wished; however she actually had gone native by then and had no desire to. While this may seem like plain old Xenophobia at first, digging into the Peacekeepers’ past with the Eidelon “Peacemakers” reveals that these people were specifically engineered to be impartial enforcers who were never supposed to take sides in a conflict. Therefore, this extreme isolation was necessary for them to retain that impartiality.
Nandi, former Companion (a ritualized and very high-class prostitute from the urban, "civilized" Core) turns tough-talking madam of a rim-world brothel. Certain episodes suggest this may be happening to Inara, the show's other companion, through her association with scruffy and unrespectable folks like Mal.
More sinister is the sole survivor of a Reaver attack on a ship. He begins to act as a Reaver because he can't mentally handle the things he saw, so he becomes the horror he witnessed. It's strongly implied that this is how the Reavers replenish their numbers.
Daenerys goes native among the Dothraki, as she was expected to, given that she was sold by her brother to their leader as a trophy wife, though their Rape, Pillage, and Burn traditions still repulse her; she is far less willing to assimilate into Qarth and Slaver's Bay, however (the name of the latter is a clue as to why).
Sansa's hairstyle grows more elaborate during Season 1 as she adapts to life in the south.
Jon Snow pretends to go native when he joins the wildlings and gains a lot of insight into them in the process and his superiors accuse him of actually going native. He's unquestionably loyal to the Night's Watch but with his frequent references to the wildlings by their own name for themselves, "the free folk", it's more than a little obvious that his time among them has had an effect. Tormund Giantsbane even lampshades this when he suggests Jon spent too much time with them and will never be a true "kneeler" again.
Mance Rayder grew up in the Night's Watch but eventually went native among the wildlings and rose to be their king. A zigzagged example, since he had been a wildling foundling taken in by the Watch to begin with.
Jaime snarks that Catelyn has become a real she-wolf (House Stark) rather than a fish (House Tully) as she became quite comfortable with her Northern home after being married off to Ned. Lysa Arryn later tells Sansa that her mother in her youth was quite a big eater and far less austere than when she was Lady of Winterfell, pointing out that she assimilated into Ned's world very easily.
Myrcella chews Jaime out when he comes to rescue her, declaring that she loves her fiancé Prince Trystane and Dorne is her home now.
Called out in dialogue in Good Omens when Crowley and Aziraphale survive the attempts of their respective superiors to execute them; it's Beelzebub's explanation for how Crowley, a demon, can lounge casually in a holy water bath.
In the second season of Heroes, Mohinder works with Mr. Bennet to take down the Company from within, but eventually becomes convinced that the Company is really the heroic organization and Bennet was misleading him.
In the JAG episode "Gypsy Eyes", after Harm & Mac have had their plane shot down by the Russian Air Force in Russia, they join a Gypsy brother and sister couple. They find out that Harm’s long lost father escaped from captivity as a POW taken to Russia, assimilated into that Romani family, died protecting them, and had even sired a son with a woman.
A different episode concerns a female naval officer who got lost, took shelter with, then joined an Iraqi Bedouin tribe by marrying into it.
Kamen Rider Gaim: Part of Kamen Rider Bravo's backstory. Born Gennosuke Oren, he changed his name to Oren Pierre Alfonzo after going to France, where he served as a soldier of their Parachute Regiment, fighting in the Middle East and Africa, in order to gain French citizenship. He also trained as a patisserie there, and is renowned as one of their top bakers. By the time he returned to Japan, he was more French than Japanese.
Lost: Locke "goes native" by leaving the 815 camp to join the Others. Also, in season 5, several of the 815ers join the Dharma Initiative and lead happy lives in the 1970s.
Mako Mermaids: An H₂O Adventure: A few of the mermaids get very attached to pretending to be humans, much to the dismay of the more misanthropic mermaids. Ondina expresses concern about how Sirena and Mimmi both got jobs and boyfriends and regularly wander around on land when their undersea chores are done. Rita and Weilan went even further, as both of them have lived on land for over a decade, being indistinguishable from humans at first glace until they get splashed.
A Running Gag in The Nanny was the Sheffields, especially Gracie, adopting stereotypically Jewish mannerisms and speaking Yiddish due to Fran's influence.
In the later series of Northern Exposure, Joel ends up living with native villagers on the banks of the river.
Downplayed but present with the Security Chiefs. Alara and Talla are Xeleyans, a culture whose species hat is that of the Proud Scholar Race, who look down on military careers and combat soldiers, despite being Heavyworlders with Super-Strength in Earth-normal gravity. Alara had a great deal of insecurity and angst over being unable to fit in with her native people, feeling more comfortable with humans. Talla comes from a family of Cultural Rebels who are considered trash by their fellow Xeleyans, and grew up in the more cosmopolitan atmosphere of the Union.
Another "Downplayed but present" comes with Isaac. A Mechanical Lifeform, he was sent by his people as an observer as well as a spy and infiltrator to learn about organics. In the course of this, he spends 700 years on a time-shifted planet observing their cultural development, starts a romantic relationship with the ship's doctor (and helps take care of her kids), and comes to feel more at home with the crew than his people enough to make a Heel–Face Turn and literally rip his leader's head off when ordered to prove his loyalty by killing his girlfriend's young son.
Likewise, the conflict with Bortus and Klyden has elements of this with some Deconstruction. Their species is a One-Gender Race that presents as male and has a nasty misogynistic streak. Early on, Bortus is forced to question his culture's gender norms when his child is born female, which forces a court battle against "correcting" the child's gender (he loses). Bortus's ex also turned out to be more into women, which is punishable by life imprisonment on the homeworld. Bortus adapting to the more gender-neutral culture of the Union (including taking orders from Kelly) while Klyden is stubbornly sticking to his guns as far as Molocan norms, has pretty much destroyed their marriage.
Outlander: After offering himself in exchange for having Roger freed from captivity, Young Ian is adopted by the Mohawk, an outcome he is very pleased with. Upon his reappearance, he has a Mohawk hairstyle and clothing, along with carrying a bow.
In Rome, Lucius Vorenus is complimented by a high-class Roman visiting Egypt for averting this. He stays true Roman while other officials in Cleopatra's court, including the triumvir Mark Antony, go native, a sacrilegious offense to Roman eyes. See the Real Life examples for more info on Antony's fate.
In Rosehaven, Emma Dawes follows her best friend Daniel to his hometown while recovering from a bad honeymoon, getting a job in his mother's real estate agency. By the end of the second series, while Emma and others claim that she's still an outsider, Daniel points out that she likes Rosehaven more than most of the people born there.
During one "Sprockets" sketch on Saturday Night Live broadcast just after the fall of the Berlin Wall, Dieter waxes poetically (and almost homoerotically) about an East German filmmaker (played by Woody Harrelson) whose films, in the opinion of Dieter, were "the perfect combination of depression, anti-consumerism, and disdain for the decadent western democracies". He then says that he is personally thrilled to welcome the filmmaker to his show. And when the filmmaker comes out, he's in a Mickey Mouse t-shirt and flip flops, Hawaiian shorts, and is toting two big bags of fast food hamburgers. Most of his interview consisted of Dieter being aghast at the man's sudden devotion to western-style democratic consumerism now that the Wall had fallen.
Sleepers, a BBC comedy-drama originally shown in 1991, tells the story of two Soviet 'sleeper' agents sent to Britain in the 1960s but all but forgotten about until 1991. Meanwhile the two agents have Gone Native and now consider themselves British, and the series depicts their attempts to evade the KGB who want to bring them back to the Soviet Union.
The trope is lampshaded when Major Grishina finds the head of the local KGB cell loudly cheering a baseball game. "What am I supposed to do, wear an I Love Leningrad T-shirt?"
In "A Hundred Days", Jack O'Neill gets trapped on a planet after a meteor hits the Stargate and buries it. He gets a quick Time Skip montage wherein he gets married and settles down, only to get rescued by the end of the episode.
In "Fallen", Daniel Jackson wakes up on a strange planet with no memory of his previous life (before or after he Ascended To A Higher Plane Of Existence) and becomes a part of the local tribe. The status quo is returned, along with his memory, by the end of the episode ... again.
Downplayed with Ba'al. After the Goa'uld are no longer the threat they once were, he hides out on Earth, developing a fondness for the culture. He's still evil, of course, but he actually picks up enough human traits that he becomes a better villain than the rest of the Goa'uld combined. His fondness for Earth is best shown in Continuum, where in an alternate timeline, his grand takeover of Earth would have involved leaving it exactly as it is, in exchange for humanity submitting to his absolute authority as God-Emperor. The other System Lords think he's gone insane.
Long time SG-1 antagonist Harry Maybourne eventually gets marooned on a low tech planet, where he uses his knowledge to make himself king. He finds that he likes being the king, and that he's good at it, so much so that he is very popular among the people he's ruling because he has done so much to make their lives better. When he gets the opportunity to return to civilization, he opts to stay.
Teal'c, after spending several years on Earth, becomes a bigger Pop Cultured Bad Ass than his teammates.
Captain Kirk does this again in "A Piece Of The Action" when he adopts the natives' ways by making himself the biggest don on the planet. Nobody's gonna put the bag over him any more!
Data does the same when he walks into a pre-industrial village with damage-induced amnesia.
Even though it is done through a Lotus-Eater Machine (a small alien probe), Captain Picard does this in "The Inner Light". He lives out a long, full life in the span of an episode (and approximately 15 minutes in-universe).
During her previous life in the body of Curzon, Jadzia Dax was one of the early Federation diplomats to start friendly relations with the Klingons. Being already kind of a boisterous hothead, Curzon Dax gained their respect and trust by becoming deeply involved in Klingon culture, learning their language and martial arts, as well as coming to highly appreciate their music and cuisine. Eventually one of his Klingon friends even named his son after him, and Dax was part of the group of four warriors who swore a blood oath to avenge the murder of the firstborn sons of the other three, no matter how long it would take to find their killer (a Klingon criminal known as the Albino). His connection to the Klingons was so strong that even when his body died and the Dax symbiote passed on to a young female scientist named Jadzia, it became a very major part of her new personalty. To the extent that when she meets Worf, the only Klingon in Starfleet, as he takes down a group of bullies with his martial arts skills, she immediately gets very interested in him and eventually ends up as his wife a few years later.
Ben Sisko went completely native over the course of the series, he started calling the wormhole aliens "Prophets", learned to read ancient Bajoran and bought land on Bajor to build a house. Several of his superiors said that Starfleet was deeply concerned by Ben's role as the Emissary and increasing assimilation into Bajoran culture, and said that they would have pulled him out if it wouldn't have totally ruined friendly relations with Bajor. Ultimately subverted in the three-part pilot of Season 7, where we learn that Sisko’s “mother” was actually one of the wormhole alien “Prophets”, thereby making him partially a native of that region. She even tells him that “you are of Bajor”.
According to T'Pol, a Vulcan expedition crashed in Pennsylvania in the 1950s and, believing that rescue was not coming, disguised themselves as humans to survive. By the time rescue did come several months later, one of their number had become so fascinated with humanity that he refused to leave, and the others finally let him stay and reported to High Command that he had died in the crash.
Gabriel/the Trickster from Supernatural fits this. An archangel, he ran away and 'joined the Pagans' and took on Loki's identity, only to eventually go up against his brother Lucifer because he actually quite likes humans and doesn't particularly want them to die. He's also shown to understand sarcasm, have normal conversations with people and blink regularly (Castiel had difficulty with those at first).
An episode of Tales from the Darkside was called "Going Native", and involved an alien woman settling down on Earth.
The Terror: "Tell them we are gone." One of them hadn't 'gone' as in died, he'd 'gone' as in this trope.
In Yes, Minister, "gone native" is a term for when ministers start to view themselves as part of their departments rather than part of the government, and get into the Civil Service mindset of hoarding money and influence for the department rather than following the government's agenda.
, a BBC comedy-drama originally shown in 1991, tells the story of two Soviet 'sleeper' agents sent to Britain in the 1960s but all but forgotten about until 1991. Meanwhile the two agents have Gone Native and now consider themselves British, and the series depicts their attempts to evade the KGB who want to bring them back to the Soviet Union.