Agent Smith: Yes, me. (transforms him into a Smith copy) Me, me, me.
Copy Smith: Me too.
One of the problems with cloning is how slow and inefficient it is; you have all the difficulties of creating life, letting the clone mature, dealing with it diverging from the original, Clone Degeneration and so on. One simple way around this is to start off with some raw materials...namely, another person. This can range from using Functional Magic or Phlebotinum to transform someone physically and mentally or using more mundane means like Magic Plastic Surgery and Brainwashing. Either way, the unfortunate victim becomes the original's Doppelgänger.
Since this basically involves killing the person the clone's "made" from, this trope tends to be the province of villains. Indeed since cloning's become possible in Real Life, (and no longer automatically brings to mind a Mad Scientist), this is a good way for a writer to keep the act of cloning someone as ethically questionable. A villain who makes a habit of it might also be The Virus (especially if the clones are able to transform people as well).
Expect all the usual Cloning Blues to be turned Up to Eleven, since the copy has to deal with a Loss of Identity on two levels; both as a copy of someone else and from losing their original identity (if they can even remember it).
Compare and Contrast; Human Shifting (where someone has the ability to transform into another person), We Will Not Use Stage Makeup In The Future (when this is used where a simple disguise would have sufficed), Body Surf, (where there is always only one of the "surfer", barring accidents), Grand Theft Me (where someone takes over another person's body), The Virus (which transforms the victim into a member of the Virus' type, rather than into a specific individual, although this distinction may be blurred if the Virus has a Hive Mind), Face Stealer (who forcefully transforms themselves into the original rather than the other way around), and Self-Constructed Being (where any material can be used as well as focusing on the being in question).
- Impure World Resurrection brings people back from the dead by turning still-living people into clones of them.
- Another technique transforms a person in a walking puppet of the controller and transforms the puppet body to match the master. These copies are only as strong as the amount of energy the controller transfers to them. When they are killed, the bodies revert to their true forms.
- In Yu-Gi-Oh! ARC-V, the card Galaxy-Eyes Cipher Dragon can take control of enemy monsters and change their names, appearance, and stats to mirror it.
- In One Piece, one of Brûlée's lesser-used powers is this. Though she mainly uses her Mirror-Mirror Fruit powers to appear in other people's mirrors and emerge through them, she also has the power to take any animal (human or otherwise), including herself, and physically alter them into a mirror image of someone or something else, Devil Fruit powers included. The effects are easily undone, however, which is why she uses it only to confuse her enemies and to stall for time.
- In The Transformers (UK), when Straxus fails into transferring his mind into Megatron's body, he turns a hapless Decepticon technician into a "Megatron clone" to attempt the transfer again.
- The infamous Clone Saga has Norman Osborn creating a copy of Aunt May via a "genetically-altered actress" while keeping the real Aunt May captive as part of his Ass Pull-errific master plan.
- Previous to this, the original Clone Saga was retconned by way of The Jackal using a retrovirus to create his clones, not the virtual instant clones as originally portrayed. Once The Clone Saga kicked off, that retcon was unceremoniously dismissed in an "I Lied" reversal.
- The Convert, one of the Justice League 3000's main enemies, does this en masse as his primary ability. It's also how the future versions of the Justice League was created.
- In DC Comics, this was the Evil Plan of four aliens who formed an alliance to take over the galaxy. They used ray guns that convert objects and people into loyal copies of themselves, possessing their powers. Their plans were fortunately thwarted by a man who caught wind of their evil schemes and got caught in a crossfire between the four of them. This left each quart of his body transformed, granting him Flying Brick, Shock and Awe and Selective Magnetism powers, so he became Ultra the Multi-Alien.
- The 2010 horror movie Victim is about a Deadly Doctor transforming a young man (who murdered his daughter) into a copy of his dead daughter through plastic surgery and brainwashing.
- The Spanish thriller The Skin I Live In has a similar premise, although the doctor in question is using a Magic Plastic Surgery technique he invented to turn his victim into a copy of his dead wife.
- In The Matrix Reloaded movie and onwards, Agent Smith gains the ability to do this (in the first movie he could only Body Surf people who were still plugged into the matrix, like all the other agents). He can do this not only to his fellow agents and other programs, but also to Free Minds to use them to gain access to the Real World. In Revolutions, by the end of the movie, he's more or less assimilated everyone in the Matrix into a copy of himself.
- Blofeld attempts this at the start of Diamonds Are Forever. James Bond KOs a scientist on the project, steals his clothes, and drowns the would-be clone in mud.
- The 6th Day justifies how fast fully grown clones can be made by making fully formed ones from "blank" clones they started growing beforehand.
- In Cinderella III: A Twist in Time, Lady Tremaine, with the Fairy Godmother's wand, turns Anastasia into a duplicate of Cinderella so she can wed Prince Charming while the real Cinderella is sent to her doom.
- Dungeons & Dragons third edition introduces the psionic power "Mind Seed" which, after a week-long incubation, turns the target into a mental duplicate of the psion (though eight levels lower than the psion when s/he infected the target).
- This power, in turn, is one of the tools the Dreaming Dark uses in Eberron.
- In the Venom's Taste trilogy, a yuan-ti psion used this power a lot. Anyone could be one of her minions (since they keep their original body). She converted chieftains, and once threatened a character's baby with it. Paranoia Fuel indeed. ~~~~
- Essence of the Wild from Magic: The Gathering operates this way, turning any other creature you cast or otherwise put into play into a copy of itself. Since they will then also have the copying ability...
- In Stardoc: Plague of Memory Cherijo's long-dead first love, Kao Torin, is sighted on the Hsktskt homeworld. He turns out to be a genetically altered Hsktskt, created from DNA extracted from Kao's corpse which was buried in space by Jorenian custom.
- In Beta, clones are created by extracting the soul of the original person (the "First") out of his/her body, then implanting a computer chip with information into said body.
- The MARZENA Series lay down the concept that certain people with neurochemically similar brains can form empathic states and become a singular mind when mentally linked up using the Bremen Chip. Connecting two similar brains together can cause the less-dominant brain to become more dominant-like (although the full effects can take months to manifest). This is what happens to Lauren when she connects to Marian's brain, fully maturing an Independent Psychological State allowing her brain to mimic Marian's brain activity, and thus break into Marian's brain-locked computer.
- In Slimer, Charlie is a genetically-engineered shapeshifting shark who absorbs the minds and bodies of his victims. Near the end, as his original body is dying, he "impregnates" the body of a Brinkstone helicopter pilot instead of absorbing him. The original body dies, while the cells implanted into the pilot convert the man's body into an exact duplicate of Charlie, with his memories and personality. Overlaps with Body Surf a little.
- In Paul Feval's Vampire City, being turned into a vampire can have this effect on the victim, which can be a little weird if they were originally a different sex than the vampire that bit them.
- Doctor Who:
- Similarly to the Matrix example, the Master does this to almost the entire human race in "The End of Time".
- In the Big Finish Doctor Who audio play Mission of the Viyrans, Peri becomes the vector for a pathogen that painfully converts the entire populace of a planet, Doctor included, into clones of her.
- Tokumei Sentai Go Busters has an unusual example of a villain doing this to himself: late in the show Enter, attempting to gain The Power of Hate for himself, deliberately begins copying more and more of Hiromu's abilities, fighting style, and eventually even his Buster form. It even reaches the point where his face begins to morph into Hiromu's at times.
- The first episode of the second season of Lois & Clark has Lex Luthor's ex-wife requesting a surgical procedure on a woman to turn her into an exact lookalike of Lois Lane as part of a revenge plot.
- A willing version of the process is very common in Visual Kei. Whether out of their admiration for other artists or out of wanting in on their success, this happens with some artists who take Follow the Leader to an extreme and become, in effect, clones of other artists' personas and sometimes even scarily close to their actual selves. Some common artists that pick up a lot of this are hide of X Japan - to the point that hide clones and cosplayers are almost their own subculture within visual kei - Kyo of Dir en grey - who was himself one of Kuroyume's Kiyoharu - and Atsushi Sakurai of Buck Tick.
- In Resident Evil 6 Ancient Conspiracy leader, Simmons created a clone of his employee, Ada Wong (who he was a little obsessed with) by testing out the C-Virus on his lover, and employee, Carla Radames. When she got her memories back, she was not amused.
- The cloning pod in Evil Genius works by copying the Evil Genius's appearance onto one of the many disposable mooks in your employ. The purpose of this is to get the mook killed in order to make the World Powers believe your Evil Genius is dead and lower your heat level.
- In Kingdom Hearts 3D: Dream Drop Distance, it is revealed that Organization XIII was designed to gather twelve Nobodies who could be subjected to this trope in order to serve as vessels for Master Xehanort's heart.
- In Tales of Symphonia, it turns out that the entire Journey of Regeneration is actually just a front for the villain to resurrect his sister via this method. The Chosen Ones are really just people specifically bred to have bodies as similar to his sister as possible.
- In Final Fantasy VII, Cloud Strife and all the turns out to be this kind of clone of Sephiroth (along with countless others who were implanted with Jenova's cells, with the amount they were injected with determining whether they just get a little power boost like everybody in SOLDIER, or end up crippled, insane, and vulnerable to having their body completely taken over by Sephiroth).
- Cloud is also one, to a lesser degree, of his dead friend Zack, whose personality and memories he partly absorbed, repressing his own due to guilt and shame after the resident Mad Scientist messed up his head. This kind of mimicry is part of the whole Jenova-cell package apparently, but it combined with Cloud's psychological trauma and major pre-existing self-esteem issues, to create a real mess of his identity
- The King of Fighters utilizes this in K's story. He's still considered a clone of main hero Kyo despite only being injected with Kyo's genes and retaining his own appearance.
- Halo reveals in The Forerunner Saga that the Didact from the Halo 3 terminals was the result of the Ur-Didact (the one from Halo 4) imprinting his consciousness upon a younger Forerunner. Unusually for this trope, the original personality still maintains some influence (most notably in his much more friendly attitude towards humanity compared with the original), and the act itself is portrayed as a necessary one, with the Didact imprint even promising his host that he'll return control when his mission is over, though by the time that happens, their personalities seem to have become irrecoverably merged.
- In Metal Gear Solid V: The Phantom Pain, Venom Snake is this to Big Boss, achieved through plastic surgery and hypnosis.
- A virus transforms many demons in Disgaea 4: A Promise Unforgotten into clones of Axel, first just acting like him, but later sounding and looking like him. The protagonists do manage to turn everyone back.
- Batman: Arkham Knight: Four individuals (Johnny Charisma, Christina Bell, Albert King, and Henry Adams) are slowly transforming into clones of The Joker due to being transfused with his Titan-infected blood, which Joker shipped out to hospitals prior to his death in Arkham City. This leads to them developing Joker's traits, such as green hair, white skin, and his Ax-Crazy personality traits.
- The Tarr from Slime Rancher will attempt to devour any slimes in its vicinity. Upon devouring a victim, it expands, and spawns a clone of itself. Water will sterilize them, and can potentially destroy them altogether.
- In The Adventures of Dr. McNinja King Radical's plan turns out to be to do this on a massive scale (more specifically converting people into the inhabitants of the Radical Lands, where he came from).
- Schlock Mercenary introduced the "REDHack" technology in the "Random Access Memorabilia" arc; State Sec's plan to capture a Big Dumb Object was to use a combination of Super Soldier and advanced medical technology to stream mind backups of one of its agents into the skins of the civilian research staff, allowing them to physically convert each victim into a Super Soldier duplicate of the agent when the activation signal was sent. A later storyline reveals that the same agency has regularly been creating sleeper agents using the same technology, who would be overwritten on-demand by the mind of the same agent. In theory, the sleeper is supposed to have a backup gestalt so they can be restored after the mission and only lose a few days of memories. In practice, the gestalts are often too out of date to be useful, and the agent usually dies during the mission anyway.
- In El Goonish Shive this starts to happen to most the guests at the party Nanase and Ellen go to.
- In Batman Beyond: Return of the Joker, the Joker implants his DNA and consciousness into a special chip installed into Tim Drake during his torture of him, causing him to turn into a copy of him many years later. Batman saves Tim and destroys Joker once and for all by shorting out the chip.
- In Avatar: The Last Airbender, the Gaang are given a creepy guide called Joo Dee when they visit the Earth Kingdom. When her veneer breaks, she's taken away and replaced by an eerily similar guide who answers to the same name and insists she's the same person. It's revealed that the city in question has an entire room full of "Joo Dee"s being brainwashed into similar guides. It's never made clear if they're based off someone, but it certainly fits the spirit of the trope.
- An episode of Ugly Americans featured a plague that was turning New Yorkers into clones of Larry King. Apparently the plague was a rare side effect caused by the original Larry King taking too many medications that interacted in an unexpected way.
- Phineas and Ferb: Dr. Doofenshmirtz's -Inator in "Night of the Living Pharmacists" has the power to turn anyone repulsive... and we see that it does this by turning people into zombie-like clones of Heinz himself that can turn other people into more Doof-clones upon contact. Chaos ensues.
- In Miraculous Ladybug, this is Monster of the Week Reflekta's primary ability.
- One episode of Archie's Weird Mysteries shows Veronica accidentally causing the populace of Riverdale to start gradually turning into duplicates of herself after making a misguided wish on a wish-granting artifact that everyone was more like her. By the time Veronica is able to reverse this, the whole town is filled with snobby teenage girls and even Archie and Betty are starting to not act like themselves.