This trope is based on the idea that a Scrappy is recognizable enough that creating a Scrappy on purpose, for purposes of parody, is a trope in itself. The reason for calling it "temporary" is that unlike an inadvertent, true Scrappy, this is never intended to be a permanent addition to the cast, even though the existing main characters usually think that he will be.
Such a character is likely to be like the original Scrappy in being a cartoon character who is too cool for his own good. He's usually a Replacement Scrappy, and his only detractor at first is the character he's a replacement for. Most of the main characters will greatly like him, and he will have every appearance of being useful to these main characters. (The audience isn't supposed to, and doesn't, like the character, however.) The character who is worried about being replaced will tend to find that his fears are justified, and the other main characters will give much more attention to the Replacement Scrappy than they did to the replaced character.
The replaced character is likely torn between sadness and resignation about the other characters finding someone better than himself, and resentment of the annoying new character who has replaced him. Fortunately, however, the Replacement Scrappy will always do something to show that he is actually bad, and it will then be okay for the replaced character to do something to get rid of the Replacement Scrappy (perhaps by proving to the other characters that he really is as bad as the replaced character had believed all along).
- When Batman had his back broken in The '90s, his temporary replacement was Jean-Paul Valley. This portrayal of Batman was an Ax-Crazy Darker and Edgier '90s Anti-Hero that sent most fans into a rage. His entire purpose was to show why the real Batman isn't an Ax-Crazy vigilante.
- The whole storyline was a response to fans complaining that Batman wasn't "hardcore" enough for the grimdark 90s because he didn't kill or brutalize his enemies. So DC called the readers' bluff by giving them exactly what they wanted. As the writers expected, fans hated it. The storyline ended with the real Batman beating down his replacement and taking back the mantle, which had been planned from the start... Please note though, that had Azbats proved lucrative, they totally would have stuck with him.
- Interestingly, Valley was still popular enough to have his own series, and the character still has fans. He'd undergone some Character Development, so he wasn't so obnoxiously hardcore by the time of his own series.
- This also happened when Captain America was replaced by his Anti-Hero Substitute, the former enemy Superpatriot. The new Cap was shown as a tool of the government first and an uncontrollable violent man later, while good ol' Steve Rogers took a black suit to remain playing hero.
- An episode of Lost in Space had The Robotoid, played by Robby the Robot, being better than the Robinsons' own Robot at nearly everything. It was, of course, evil, and The Robot had to save the day.
- Interestingly, Robby the Robot was used in a similar manner on The Addams Family, where he was doing the same thing to Lurch.
- Doctor Who
- Adam Mitchell joins the Ninth Doctor and Rose Tyler at the end of "Dalek". He is promptly ejected from the TARDIS at the end of the next episode, "The Long Game". after using time travel for a get-rich-quick scheme, accidentally helping the villains, and then trying to blame the Doctor and cover up what he'd done. Russell T Davies explained in an interview that he "always wanted to do a show with someone who was a rubbish companion."
- Herbert, the one-off comedy companion in "Timelash", also qualifies. With Peri stuck on the planet of the week, Herbert does the companion schtick in the TARDIS while the Doctor is trying to use the Ship to stop an interplanetary missile. This includes constantly running his mouth, boasting about wanting do die bravely, and generally making enough of a nuisance of himself that the Doctor eventually tells him to shut up. (It doesn't work.)
- Buffy the Vampire Slayer
- In the third season, Wesley Windham Pryce was intended to be this trope (he was even named Wesley) and killed off in the "Graduation" episode. However, he accidentally became popular, joined the cast of spin-off Angel, Took a Level in Badass, and stayed on the show until the final episode.
- In the fourth season, after Buffy and Angel had broken up, in order to ease viewers into her next major love interest Riley, a Romantic False Lead named Parker was created for Buffy to briefly get together with, only for him to reveal himself as a womanizing jerk who immediately ditched Buffy after having a one-night stand with her. He then spent a few more episodes appearing and usually ended up suffering some sort of humiliation by the end of them.
- Seems to the the purpose of Deangelo Vickers on The Office (US). Introduced as the first replacement for Michael, he was consistently written to be a horrible person in general with apparently no experience in business. Many fans cried Replacement Scrappy, but he was only intended to last one episode past Michael's exit anyway.
- Captain Dozerman from Brooklyn Nine-Nine was similar to Deangelo. He was brought in as an unlikable replacement for Captain Holt, and was then Killed Off for Real after just one episode, leading to Holt's eventual return.
- Lady Vivian on Merlin was introduced in one episode as a snotty Spoiled Brat who Arthur fell for whilst under the influence of a love spell, and then ushered out again once he snapped out of it.
- Dale Stuckey, from Law & Order: Special Victims Unit, was a crime scene unit tech who tried to make a name for himself among the other SVU members, only to get on everybody's nerves, especially Elliot Stabler. Eventually, after botching a trial due to a paperwork error causing crucial evidence to be ruled inadmissible, he goes off the deep end and tries to kill everyone he felt wronged him, including stabbing his coworker and torturing Stabler. He was featured in three episodes total, and is now presumably rotting in prison.
- ADA Sonya Paxton was featured for a few episodes, and managed to annoy every detective in the SVU: her relationship with Stabler was especially hostile. After a few episodes, she is Put on a Bus, sent to rehab after blowing a case when she arrived to court drunk. She appeared in a couple more episodes in the proceeding seasons.
- When Lt. Fancy left on NYPD Blue his replacement, a former Internal Affairs officer, managed to irritate every single squad member as soon as she showed up. Fancy, wanting to help out his loyal former subordinates, used some pull with the higher-ups to get her replaced with Lt. Rodriguez.
- Leverage had Jeri Ryan's character Tara Cole, brought in for the second half of Season 2 to accommodate Gina Bellman's maternity leave, with the in-story explanation being that Bellman's character, a con-woman named Sophie Devereaux, had created so many false identities, she had lost herself in the process and in order to find herself, she had to go and kill off her other personas. Despite being clear from the start that Tara was only going to be around temporarily, that didn't stop her from grating with the characters and the audience in roughly equal measure, primarily for being much more cold and detached, and for being much more explicit about wanting her cut of whatever profits their cons brought in (she missed the team's first mission, which made the rest of the crew independently wealthy and left them helping others simply because it felt good, so her desire for her cut wasn't unreasonable.) However, furthering the problem was that she was introduced mid-con, already in-character, and generally spent very little time out of it, meaning it was hard for the characters and viewers to relate to the character behind the masks. She did do a good job of showing how well the original team fit together, though.
- The Annoying Orange episode More Annoying Orange has the titular More Annoying Orange who's so nerve-grating that he annoys the original Annoying Orange. At the end of the episode, the more annoying orange gets cut up and is made into orange juice...but then six more annoying oranges are brought in.
- Family Guy
- In "The Man with Two Brians", after Peter starts worrying about Brian getting old he goes out and gets the family another dog known only as "New Brian." Guess who feels jealous of him. Brian and Stewie both dislike New Brian, but all the other characters think he's great. Near the end of the episode, New Brian admits to Stewie that he violated Stewie's teddy bear (Rupert). The next scene has Stewie giving Peter, Lois, and the other characters a quite suspicious story about how New Brian committed suicide, then cut himself up, bagged the pieces, and put the bag in the trash outside.
- And then, there's Vinny, who replaced Brian after he is killed. He's quickly accepted into the Griffin household and accepted by all, even Stewie despite the incident above. Then, Stewie runs into one of his time traveling selves and uses the opportunity to save Brian. Vinny, seeing how Brian's loss was still affecting Stewie, helped out with the plan (even though doing so meant he would have never been adopted by the Griffins in the first place).
- On American Dragon: Jake Long, Jake's normal Non-Human Sidekick is a dog named Fu. And in one episode, he's replaced by a monkey named Bananas. Bananas acts excessively cool and has many useful skills, thus making Jake and most of the other characters like him. However, in the fight against a Monster of the Week evil dragon, Bananas surrenders and goes over to her side. Jake appreciates his more loyal friend Fu once more, and Bananas' only other appearance is when his new dragon mistress reappears in a later episode.
- On The Simpsons episode "The Itchy & Scratchy & Poochie Show", the Show Within a Show Itchy & Scratchy had a dog named Poochie, who was hated by the audience of characters on the show proper, leading the producers to Shoo Out the New Guy. There was also another character added to the episode who was a parody of Scrappys everywhere: a teenager named Roy who was inexplicably shown to be living with the Simpson family; however, all Roy did was hang lampshades on the concept of a Scrappy.
- In one U.S. Acres segment in Garfield and Friends, an overly-charismatic new rooster named Plato shows up and proves to be far more likable to the characters (especially the hens) than Roy. Orson starts to doubt him when he proves a little less effective at his job than Roy, but what takes the cake is when the weasel tries to capture the hens... and Plato runs and hides. By the time Roy rescues the hens, the only character who will even give Plato the time of day is Wade... and only because he enjoys having someone more cowardly than himself around.
- The Avengers: Earth's Mightiest Heroes! had the Red Hulk weasel his way onto the team in place of the regular Hulk; partly because he was on his best behavior and claimed his prior villainous actions were the result of Brainwashing, and partly because "better teammate than the Hulk" isn't a high standard to reach, especially since the Hulk had been more out of control than usual recently. Since the Hulk was either rampaging or locked up for most of the episode, Captain America took the role of the one suspicious of the newcomer. Cap eventually broke the Hulk out of lockup and found that Red had rigged Hulk with an implant to trigger his rage - of course, finding out that someone manipulated him made the Hulk mad...
- Pinky and the Brain had an episode called "Pinky and the Brain... and Larry" in which Pinky and the Brain are joined by a third lab mouse, Larry, who serves no purpose except to be a parody Scrappy and disappear for good at the end of the segment in which he appears.