The brain of one character somehow finds itself in the body of another. Requires actors to confront an actor's nightmare, i.e., acting as if they were another actor.
The most benign subtrope of Body Snatcher: two or more characters swap bodies (or, equally, swap minds) by some form of magic or Applied Phlebotinum. Typically, a deeper appreciation of the other's life is attained. Named for a novel and movie about a body swap between a mother and her daughter.
To be really convincing, the actors may have to mimic the body language and speech patterns of the actor they are supposed to have switched with - ie, an older person using very modern language and slouching. This is doubly complicated if they are trying to imperfectly pretend they are the other person.
When this plot is done in animation, usually the voices also switch as narrative cheat to help younger viewers keep track of who's who. More subtly, it's just the eyes. More serious/action-oriented shows might not do this. The Flip often involves characters of different ages, genders, races, or social classes. Another variation is a protagonist and antagonist switching, which usually involves each trying to undermine the other's organization while simultaneously trying to switch back. Alternatively it may lead to a HeelFace Turn. If one or both of the characters have superpowers or other special abilities, they'll have a lot of trouble figuring their new powers out.
A similar idea, with less learning and more evil, is Grand Theft Me. Compare Personality Swap, when the characters' personalities are swapped but their minds stay where they are meant to be, and Transferred Transformation. Contrast with Physical Attribute Swap, when two characters exchange specific physical traits like height, weight, or age without switching bodies entirely. Mental Time Travel might be a temporal variation of this. It will often involve similar tropes to transformation stories (such as Gender Bender) as this is essentially two of these in one, with the addition of confusion resulting from the transformations being into other known characters.note
Nearly an Obligatory Joke in some genres (as in, bound to happen sooner or later in the series, if it's popular enough).
In the more traditional applications of the trope, the reason of the switch is never explained in-universe. However, the Doylist reason for any application is often to force the age-old moral: To better understand others, you must experience life in their shoes.
- Anime & Manga
- Comic Books
- Fan Works
- Films Live-Action
- Live-Action TV
- Video Games
- Western Animation
- A T-Mobile advert from 2003 shows a woman getting a video message from her husband. The video shows her young daughter activating her science project; a brain switcher, which swaps her older brother's body with the family dog. The dog speaks with the son's voice while the boy lifts his leg to scratch behind his ear. Cue mom fainting. A very brief scene after this shows the dad playing fetch with the dog in the boy's body.
- From the 2016 European Championship, Nike's "The Switch" deals with this happening between Christiano Ronaldo and an English boy.
- Lamput: In "Transfer Gun", the Boss invents a ray gun with this effect. The Boss and Lamput get hit by shots from the gun by accident, and the Boss in Lamput's body initially has trouble getting the docs to believe he's not actually Lamput.
- In the Motu Patlu episode "Soul Change", Ghasitaram tricks Motu and Patlu into entering a body-swapping machine made by Dr. Jhatka. The two confuse Chaiwala when they go to his samosa stand and he assumes that Patlu is eating samosas while Motu is reading the paper - the exact opposite of what they would normally do.
- One episode of Tobot has Limo mixing up the Mind Cores, resulting in them being placed in the wrong bodies. Specifically, Tobot X's Mind Core is in Tobot D, Tobot Y's is in Tobot R, Tobot Z's is in Tobot X, Tobot D's is in Tobot Y, and Tobot R's is in Tobot Z.
- Happens to Donkey and Puss-n-Boots in Shrek the Third.
- In a scrapped scene in Cars, Lightning is given a choice of participating in a race or doing community service. When he picks the community service, he wakes up the next day and finds that his engine (apparently the car equivalent of a brain) has been put into a steamroller, much to his horror, and Mater's engine has been put in Lightning's body, which he uses to take over Lightning's life. Fortunately, this is All Just a Dream, but when he wakes up he fearfully changes his mind and decides to do the race instead.
- In the seventh Pleasant Goat and Big Big Wolf film, Wolffy has a body-swapping rug with him when he, Paddi, and Weslie are all transported to the prehistoric age. He and Paddi are on the body-swapping rug when they're transported, causing Wolffy to wind up in Paddi's body and vice versa for part of the movie.
- Downplayed in the Winnie the Pooh movie Winnie the Pooh: A Very Merry Pooh Year. Pooh and his friends make a resolution to "change" so they can stop Rabbit from moving away, and end up switching their personalities. Piglet begins to bounce and and conquers his fears, while becoming the goofball that Tigger is, while Tigger gives up bouncing and ends up catching Piglet's Nervous Wreck nature. Eeyore tries not to be gloomy and starts acting like Pooh, becoming constantly jolly and eating honey, right down to wearing Pooh's red shirt. Pooh himself, on the other hand, decides to stop eating honey himself, and as a result, becomes gloomy like Eeyore complete with Dull Surprise.
- In Johnny Cash's song "Chicken in Black", Johnny's "body's outlived [his] brain", so he is given the brain of a recently killed bank robber. And Johnny's brain winds up in a chicken. Hilarity Ensues.
- The song "Freaky Friday" by Lil Dicky and Chris Brown, as you may guess, is about the two of them swapping bodies for a day. Dicky quickly winds up enamored with his celebrity friends and lifestyle, his R&B singing voice, his bigger penis, and his newfound N-Word Privileges, while Chris is initially happy to be away from his scandal-filled personal life, until he realizes that he might never see his daughter again and that Dicky is acting like a fool in his body. ("My dick is trending on Twitter? Fuck!") At the end, Dicky also hops into the bodies of Ed Sheeran, DJ Khaled, and Kendall Jenner; with the last one, he immediately starts feeling up his new body.
- Dungeons & Dragons
- The Mind Switch and True Mind Switch spells. While Mind Switch is only semi-permanent, True Mind Switch is completely permanent and can only be undone by another True Mind Switch.
- Before this, 2nd edition had the "Switch Personality" telepathic science from The Complete Psionic Handbook. It allows the psionicist to switch mind with another creature, but any prolonged use is dangerous, as both bodies tend to degrade when inhabited by the wrong mind.
- The Complete Book of Necromancers also introduced the "Life Force Exchange" spell, which is permanent and can be used on any two creatures (including or not the caster). It is one of two powerful spells allowing aged necromancers to abandon their old body for a new, younger and stronger one.
- This is just one condition that the Alchemist's Apparatus, an evil device found the Ravenloft setting can create. (It can also split one being into two bodies, one good and one evil, or merge two beings into one body.) The only way to reverse any of this device's effects is to use it a second time, and using it at all is incredibly dangerous. (Not only is it prone to blowing up, it tends to drive the victims insane, requiring Ravenloft Powers checks for the user and Madness Checks for the victims. Unfortunately, even when it does blow up, someone always rebuilds it later.)
- Triggering this trope is just one of many ways to get grounded in Go Animate "Grounded" videos. For one example, this video involves Caillou switching bodies with his mother in an attempt to avoid getting grounded. Unfortunately for Caillou, the switch lasts for all of about 20 seconds before he and his mom switch back, after which he is given additional grounding time for the swap. Voices Are Mental tends to be in effect whenever this occurs.
- Dr. Havoc's Diary: Episode 24, appropriately called "Freaky Friday". All thanks to one of Havoc's machines, this happens between Ally and Havoc, and then various other characters as well. Oh, and Voices Are Mental is averted.
- The Britanick video "A Monologue for Three" ends with a four-way body swap between Brian, Nick, Danny Pudi, and . . . well, you'll just have to watch it.
- There is a web series made by Three friends from Florida called Freaky Forever. It can be watched here.
- In the LoadingReadyRun video "Brain Transplants Made Easy", Paul does this to everyone just to prove a point. This is taken to the hilarious extremes of Jer getting switched with Dana (a random stranger) and Bill getting switched with Gib (a puppet).
- Noob has a dungeon that will cause an avatar switch between two players after the first boss gets beaten. Voices don't change despite the fact that it would actually make sense.
- This happens to all the main characters in The Devil Is a Part-Timer!'s Halloween OVA.
- Used in the episode, "Switching Bodies!". Chef Pee Pee and Bowser Junior both go to bed wishing what it's like to be each other, and then wake up the next morning with their bodies switched. Hilarity Ensues, surprisingly. This is soon exploited when Chef Pee Pee-as-Junior tells Junior's friends to take his toys, and Junior-as-Chef Pee Pee angrily gets back at him by telling Bowser to start beating, strangling, insulting and paying him, knowing that Chef Pee Pee will get blamed for saying that.
- Used again in the episode, "Life Is Ruff!". Junior and his pet Chain Chomp, Chompy get hit by Woody's truck, and somehow end up in each other's bodies. The entire episode is a Whole Plot Reference to the 2005 Disney Channel Original movie of the same name.
- Used yet again "1 2 Switch Bodies!", wherein a lightning bolt strikes Junior and Jeffy while they are playing 1-2 Switch on the Nintendo Switch, switching their bodies as a result. Near the end of the video, the exact same thing happens to Chef Pee Pee and Cody.
- When Body Switching Movies Collide is a skit done by the Cracked staff. It starts off when Sam Beckett Leaped into Ellen Cunningham's mind after she switched bodies with Anna. Sam Cunningham, Ellen's dead husband, shows up, explaining how he will possess Sam and have sex with Ellen one last time. Al argues that Sam Cunningham possessing Sam Beckett to have sex with Ellen would result in Anna's body having sex with Helen, who has Anna's mind at the moment. The Ghost Sam leaves in disgust, saying he plans to have sex with someone else. Al reveals that Anna is a secret agent hired for the Stargate project in the Torchwood Institute in Roswell. Trinity, who works for the Millenium Group, shows up in a Slider Hole and explains that the world is a false reality created by sophisticated computers contained within the mind of John Horatio Malkovich. When Sam Beckett asks Al to Leap him out of this madness, Al can't because he's actually a Cylon. It turns out it was all Michael Swaim's dream, and the camera zooms out to reveal that sequence was imagined by Michael looking at his snowglobe.
- SMG4's Mario Bloopers pulls this off accordingly, not once, not twice, but three times.
- "The Switcheroooveralls". Mario, SMG4 and most of the gang switch their color codes in this blooper. Hilarious antics ensue, including a crazy Indian mistaking FM54321 for MCGustavo, and attempting to chase him as revenge for stealing his toilet, Luigi, in X's body, becoming friends with a Toad zombie he calls "Brains", and Toad even becoming a rock, forced to spend his time with Bowser after accidentally getting thrown towards his lair.
- The episode "The Swap", where Mario annoys a wizard to the point where he switches his and SMG4's bodies as punishment. It doesn't help that SMG4 is applying for a job as a janitor.
- "Mineswap" has this. Mario starts to break a scientist guy's machine as Steve mistakes it for chocolate, leading to the two swapping body shapes; Mario becomes a Minecraft model while Steve is a Super Mario 64 color code. This is defied since in the end, the machine is destroyed and Mario and Steve are still in their opposite body shapes.
- In one episode of The Time... Guys, Doc Chronos invents a brain-switching device. Turns out he can only invent time machines.
- In Ducktalez 3, Vegeta pulls a Captain Ginyu on Scrooge McDuck. Vegeta gets Scrooge's art style and Scrooge gets Vegeta's art style. Dewey and Louie immediately wonder why Scrooge looks crappy.
- How to Hero has a whole entry on mind-swaps.
- Scientists have found that by syncing a pair of VR goggles on one person's head with a set of cameras on a mannequin or another person's head, the brain is fooled into believing that they are in the body of the mannequin or the other person. Again, no, seriously.