Remember The New Guy / Western Animation

New characters who need no introduction in Western Animation.

---

Examples:

• 101 Dalmatians: The Series: Spot only appeared in one scene of Home is Where the Bark Is (asleep, no less) then in the next episode, she was friends with the main trio without explanation.
• The Adventures of Puss in Boots: Occurs In-Universe in the episode "Remember Me Not". "Li'l Pequena", who is really a malevolent fairy disguised as an orphan girl, gradually starts appearing among the other orphans throughout the course of Season 5. No one seems to notice her, all believing that she'd always lived in the town. She had been changing everyone's memories, to the point that we see flashbacks of scenes from earlier in the series edited to include her - which might even make viewers doubt their own memory.
• Adventure Time: The King of Ooo wasn't introduced until the season 5 episode "Apple Wedding", but Princess Bubblegum's outraged reaction to hearing he's officiating the wedding of Tree Trunks and Mr. Pig shows the two have a history.
• In American Dad!:
  • An odd example happens in Season 6, when Reginald the Koala becomes a major supporting character and is even living with the Smith family for no explained reason. The Smiths act like he's always been there, even though he's only appeared twice before in a previous season (and barely interacted with them at that.)
  • This trope was also parodied in one episode, when Francine meets her apparently best friend at her high school reunion. He never appears beforehand (or afterwards), but Francine apparently mentions him a lot.
    Francine: This was my best friend in the entire world, Quacky.
    Stan: Then how come I've never heard you mention him once?
    Francine: I mention him all the time. I even did that one-woman show, "Mentioning Quacky".
    Stan: Oh yeah. I meant to go to that.
  • This trope is parodied again in the episode "Death by Dinner Party" which has the appearance of a new character called Colonel Whitersby, who everyone, including the Smiths' friends, treat as a longtime friend who's always been around, despite this being the first episode he's appeared in.
• Lucas Troy from Archer, who qualified to work for ISIS back when everyone was just starting, but opted to work for ODIN instead. Despite being the best fit for Archer's Friend Turned Rival, he's never been mentioned before his first appearance.
• Arthur: The special An Arthur Thanksgiving introduces us to Aunt Minnie, Arthur, D.W., and Kate's aunt who lives in France and is visiting for Thanksgiving. Arthur shows a picture of a previous Thanksgiving in which she was there, although Minnie's only previous appearance on the show is a minor role in The Rhythm and Roots of Arthur. This is partially lampshaded, as D.W. can't even remember Minnie and doesn't trust her at first.
• Atomic Betty: Mission Earth introduced Penelope Lang's brother Chaz and Principal Peterson's daughter Regeena. It's handwaved that Chaz was previously attending boarding school, but no explanation is given for why Regeena wasn't already going to her own father's school.
• Baby Looney Tunes had Petunia Pig and Melissa Duck. They simply appear midway through Season 1 with no explanation and the other babies and Granny act like they were always there.
• Beast Wars has this with Depth Charge in season 3. He's an old enemy of Rampage and a guy who tried to convince the Maximal Elders to execute Rampage, which Optimus Primal argued against. He's never mentioned before his first episode. The massacre Rampage is supposed to have performed that made Depth Charge so revenge obsessed is not mentioned by Optimus in previous episodes when he mentions Rampage's origin. He's simply called "treacherous and insane". Apparently the fact he murdered a colony and a star base (and ate some of them) was not worth mentioning. Neither that a lone survivor from the aforementioned colony tracked him down and captured him. Downplayed though, since as far as they knew Depth Charge was a trillion miles away and centuries in the future, there really wasn't a lot of reason to mention him.
• Ben 10:
  • Ben 10: Alien Force gives us Ken, Gwen's older brother who had only been briefly named in a Pop-Up Trivia entry in the Original Series and had never been mentioned or appeared in show proper. After that he never appears again. Suggesting he was brought out of limbo solely to give Max a reason to come out of hiding.
  • Ben 10: Omniverse handwaves most of the "New Guy" moments by Ben imperfectly rebuilding the universe after he kinda blew it up.
    • The series has Ben using the Feedback form in flashbacks to when he was 11 years old, even though it has never been seen in any of the other series. Even bigger, the form is portrayed as his favourite alien, despite all previous shows having Ben's first choice for most situations (at least when the Omnitrix lets him pick) be a huge muscular bruiser like Four Arms or Humungousaur. Lampshaded by Gwen, who asks him at one point why he's suddenly always using Feedback. This is somewhat justified by the fact that losing his alien form to Malware was such a traumatic experience that Ben decided to try and forget about it.
    • Parodied with Billy Billions. Remember Ben's rival from back in 6th grade? Neither does Ben.
• Big City Greens: Parodied in “Long Goodbye”. Upon returning to Big City, nearly all of the supporting cast show up to greet the Greens, followed by a new character named Fabian the Puzzle-Master, who acts as if everyone remembers him. The Greens have absolutely no idea who he is.
• The Biker Mice from Mars episode "Diet of Worms" had Lawrence Limburger form a meeting with three other Plutarkian bosses: One-Eyed Jack Monterey, Gerald Gruyere, and Gutama Gouda. The Biker Mice recognize One-Eyed Jack Monterey and Gerald Gruyere even though they didn't appear in any previous episodes.
• The final episode of Bunnicula suddenly introduces Bunnicula's brother.
• Inverted in Care Bears & Cousins, probably to set up for the Fleeting Demographic Rule^note The cousins had not been seen for over two decades, 11-13 years if you count in Play Along Toys' failed attempt to reintroduce them in the early 2000s and or comedic effect. In the first episode, none of the bears except Tenderheart knew who the cousins were.
• The prequel to Clifford the Big Red Dog, Clifford's Puppy Days introduces Daffodil as Emily Elizabeth's pet rabbit. She is not present or even alluded to in the sequel which causes Fridge Horror of what could have happened to her since.
• Parodied in an episode of Clone High. Not only is it established (and repeatedly lampshaded) that the hitherto unseen Ponce de Leon is one of the most popular students at the eponymous high school, but he's also best friends forever with main character JFK (who has a BFF tattoo on his left arm—seriously, it borders on sheer Ho Yay). And, oh yeah, Ponce dies in the same episode.
  Julius Caesar: Oh, Ponce, you're a regular character!
• In The Cleveland Show, Cleveland's friend circle abruptly added in a sixth member, this being a generic background guy named Franklin. Their explanation to his presence was that he just started hanging out with the guys a week ago, and Franklin said that he looked forward to many future adventures and wacky hijinks with the old crew for years to come. Immediately after his on-screen debut, Franklin died in a game of Hurt Locker gone wrong, and it was treated as a tragic event by the rest of the cast. His friends, family, and other actual recurring characters were mourning over their tragic loss at his funeral, and of course, he was never seen or mentioned again, seconds after the funeral scene ended.
• In Code Lyoko, Yumi's brother Hiroki is first seen in Season 2. He is never mentioned in Season 1, even though the Ishiyama family and home are often involved on-screen.
• Codename: Kids Next Door: "Operation: M.A.U.R.I.C.E." introduces Maurice, one of the most beloved operatives of the KND. All five of the main characters are familiar with him. This is somewhat justified as Maurice had been away for a few years on a mission.
• Cyberchase has Wicked's wand Wanda who only appears in "Designing Mr. Perfect". While Wicked's wand has been around for as long as Wicked, it hasn't been shown as a sentient being before. However, everyone seems to be aware of this and know her by name with no introductions necessary.
• Parodied in the series finale of Drawn Together, where a character is "voted" off the show. After much suspense the character revealed to get the boot was Munchkin Mouse, a character never seen in any episode of the show. All the characters are shocked to see Munchkin Mouse go and a montage of "Munchkin Mouse's Greatest Moments" is played featuring the same image of Munchkin Mouse spliced in to memorable scenes from the show.
  • Similarly done in "A Tale of Two Cows". Even though Wooldoor Sockbat only met Live Action Cow at the beginning of the episode, there's a montage at the end of him remembering the good times he had with her, which is really shots from other episodes with Live Action Cow crudely inserted in. There were even scenes that Wooldoor didn't originally appear in, with him and Live Action Cow often replacing characters that were involved with the original scene.
  • In an earlier go-around of 'cast member gets kicked off', it's Excludie, the character everyone excluded from their activities. This is even parodied where the others were dying of cold, and Excludie was given a warm blanket and something warm to drink so he could not die with them.
• Elena of Avalor:
  • Invoked by Carla Delgado when they pose as Armando's cousin to infiltrate the palace. Armando (picked because he'd be the type of person to fall for this) doesn't remember them at first, but quickly accepts that they must be cousins, with the rest of the cast taking his word for it.
  • Played straight with Elena's cousin Cristobal, introduced after Esteban was established to be her only cousin. The fact that they weren't close might have played a part in his Face–Heel Turn, but that isn't alluded to.
• Elinor Wonders Why: "A Garden for All" is the first appearance of Hazel, yet the characters act like they always knew her.
• The Fairly OddParents!: In season 10, the Squirrely Scouts are inexplicably replaced by an entirely new cast of kid characters, rather than the established ones seen earlier. They're not given proper introductions and aren't treated as new recruits, and the show acts like they were always there.
• Franklin introduced several characters' younger siblings in this way, most notably Kit, who was introduced as being near preschool age in Back to School with Franklin, even though Beaver had never been referenced as having a sibling before in five seasons of the show. He was never seen again, either.
• Futurama:
  • Played for Laughs with Scruffy the Janitor, the eighth member of Planet Express, who first appeared in "Anthology of Interest I" when Farnsworth gathered the crew to test out his What-If Machine. It's a Running Gag that most of his coworkers either barely know him or don't know him at all, and it seems he'd prefer to keep it that way. ("Anthology of Interest II" continues the gag with two other Planet Express employees who are never seen again, a Spock-like character called Xanthor and a fairy named Katrina.)
    Scruffy: I've never seen him [Bender] so down. Or ever before.
  • Played for Drama in "Jurassic Bark", which Retcons Fry's dog Seymour into the events of the pilot episode. It seems he was at Panucci's the day Fry took off on his final delivery, we just never saw him. It's poignant precisely because it serves to emphasize something that the show usually doesn't dwell on: the fact that Fry had a life of his own before he arrived in the future, even if it was mundane, and his family and friends were all affected by him suddenly and completely vanishing one New Year's Eve.
• Hi Hi Puffy AmiYumi has Julie, the former third member of the band, return for a reunion tour in the episode "Julie AmiYumi". The reason we never saw her before was handwaved by the explanation that Ami hated Julie, who treated her like crap, and didn't really want to talk about her ever again.
• Portia pops up in an episode of Holly Hobbie and Friends. The characters reference past things and how she's acting odd but it's hard to understand as she's a new character.
• The Phantom Blot only appeared in two Mickey MouseWorks shorts: "Mickey Foils the Phantom Blot" and "Mickey and the Color Caper", the latter being one of the MouseWorks shorts that debuted in House of Mouse. In spite of those shorts being his only two appearances, the Phantom Blot is implied to have menaced Mickey and his friends for quite some time. In "Mickey Foils the Phantom Blot", the Blot tells Mickey that he and his friends have met him again for the last time. "Mickey and the Color Caper", which appeared on House of Mouse before "Mickey Foils the Phantom Blot", had Mickey rather quickly figure out that the Phantom Blot was to blame for the disappearing colors. Justified, since The Phantom Blot is a character who actually existed in the Mickey Mouse comic books.
• I ♡ Arlo: The Bog Lady crosses this with Forgotten First Meeting, as she had been secretly protecting Arlo since he first came to the swamp as a baby, but he didn't even know of her appearance until she lured him back fifteen years later. He was also surprised she knows his name, thus she had to let him in on it.
• Invader Zim:
  • Lampshaded in the Christmas special, where Zim insists Minimoose has been with him the entire time. Word of God says that, time permitting, there would've been a little montage of scenes from previous episodes with Minimoose crudely taped onto the picture at that point. The real reason for this discrepancy is that the Christmas special was intended to appear after an episode introducing Minimoose, but when the creators realized the show was soon to be cancelled, they made the more-profitable Christmas special early without regard to continuity.
  • Zim tried to invoke an inverted form of this trope when he pretended to know who Dib was after joining his class in the very first episode.
• After its first season had middling ratings, Johnny Bravo was ReTooled during its second season, which introduced two new regular characters: Carl Chryniszzswics, a nerd who insists he's Johnny's best friend, and Pops, mentor to Johnny and owner of a local diner and quite possibly a few other, sketchier business ventures. They are treated as though they always existed despite not appearing nor being mentioned in the first season. After the show returned to it's original style in the fourth season, Carl was Demoted to Extra and Pops only had a brief non-speaking cameo in one episode.
• Kid Cosmic: Parodied with Skippy Olsen, a character who only appears for one episode in Season 3. When he appears, Kid and Papa G immediately know who he is (and act like he's a beloved friend) but Jo has no clue who this guy is.
• The Legend of Korra: The third season introduces Lin's estranged half-sister Suyin. She was never mentioned before by anyone and it was never implied Lin had siblings. The in-series justification for this is that the two haven't seen one another in years and aren't on good terms.
• The Lion Guard: The main character is a never-before-seen son of Simba and Nala called Kion despite the fact Kiara was the only cub in her pride in The Lion King II: Simba's Pride. Kiara is still around, though she's inexplicably still a cub despite having been an only child throughout the second film. There are also two new cubs despite the fact Kiara was the only cub in her pride according to Simba's Pride, and Timon and Pumbaa have an adopted nephew named Bunga. The Lion Guard has attempted to tie itself into the original film, though it's still vaguely in an Alternate Continuity. Season 3 of The Lion Guard takes place around the time of the second part of Simba's Pride (when Kiara's now a young adult), and the first episode sees Kion and his team leaving the Pridelands on a long journey, thus explaining why they're away during Kiara's first solo hunt and beyond.
• The Magic School Bus Rides Again features a different teacher from Ms. Valerie Frizzle—her sister Ms. Fiona Frizzle. In the original cartoon, a large number of Ms. Frizzle's family was either seen or referenced (including her brother John), but she never mentioned having a sister named "Fiona".
• Mega Man (Ruby-Spears)' title character would sometimes namedrop whatever new Robot Master that Dr. Wily brought along for that week's adventure, implying he'd fought them before in some world domination attempt the viewers didn't get to see.
• According to Word of God, Milo Murphy's Law is set in the same universe as Phineas and Ferb and Milo was always around, but he never got involved in P&F's big ideas due to his bad luck.
• Miraculous Ladybug:
  • In season 4, we learn that Chloe had a half-sister named Zoe who had been living with her father in New York. Marinette, the main character, can at least be excused for not knowing (she and Chloe don't get along), and it's not even clear how long Chloe knew about her, but Chloe at least knew before Zoe's introduction. The viewer was not let in at all.
  • Then there is Socqueline, introduced in season 5. Apparently, she was a long-time friend of Marinette's who had defended her against Chloe, and who had inspired Marinette's trademark pigtails. She's a year older than Marinette and no longer attended the same school, but she didn't appear or get name-dropped even once before season 5. Which raises the question: when selecting friends of hers to become superheroes, why did Marinette never consider diehard do-gooder Socqueline?
• My Little Pony:
  • My Little Pony TV Specials: Taken to an extreme in "Escape from Catrina", where Megan and Spike are the only characters held over from the earlier special. Slightly justified, as there are a lot of ponies.
  • My Little Pony 'n Friends:
    • The show doesn't include any ponies from the previous specials, instead introducing a new cast of regulars whom Megan is already familiar with.
    • Mimic debuts in "The Golden Horseshoes, Part 1", well into the show's second season, but is introduced as a familiar character whom the others are already well-acquainted with.
  • My Little Pony: Friendship Is Magic occasionally names ponies that have never appeared before:
    • Miss Cheerilee's class frequently has new students suddenly show up and be treated as if they've always been there by the others.^note Since there are only nine seats or so in the room, it's possible that they simply rotate schedules. A prominent example would be Featherweight, who was a blank-flank until his introduction, despite a plot point of an earlier episode being that the Cutie Mark Crusaders were the only blank-flanks left in their class.
    • "A Canterlot Wedding, Part 1" introduces both Twilight's brother Shining Armor and her former foalsitter Princess Cadance. Twilight claims they were her only real friends before she moved to Ponyville (despite her earlier statements that she didn't have any friends before then), which makes it odd that we never hear about them for the first two seasons of the show, the latter especially due to her role as Princess. The rest of the main cast are extremely confused as well; they've never heard either one mentioned before either.
    • Maud Pie stands out in that an earlier event is retconned to include her. When Pinkie's origin story is shown in flashback in season 1's "The Cutie Mark Chronicles", we see her with two sisters, Limestone and Marble. In Season 4's "Pinkie Pride" a picture from the exact same scene appears, showing Maud as a fourth filly with no explanation given as to why we didn't see her in the earlier flashback.
    • In "The Mane Attraction", we are introduced to Countess Coloratura. According to the characters, she is the "biggest pop star in Equestria", and act with stunned reaction at Applejack when she asks who she is. Considering Countess Coloratura has never been mentioned before in the show despite her supposed "fame", audiences ended up relating more with Applejack.
    • In "Flutter Brutter", we meet Fluttershy's brother, Zephyr Breeze. Much Like Shining Armor and Maud Pie, he comes right out of the blue with no foreshadowing. Unlike Shining Armor and Maud Pie, the mane six act like they've heard of and even met Zephyr before, with Dash definitely familiar with him. Though given what kind of pony Zephyr is, it is perhaps understandable that they wouldn't want to talk about him...
• The Owl House: The episode, "Eclipse Lake", introduces us to Amity's new palisman, Ghost. No-one seems surprised to see it, implying it's been around for a while. Justified as Willow mentioned that Amity has been hanging around the Owl House a lot lately, implying that she got Ghost during this time period.
• Peanuts: The special Why, Charlie Brown, Why? introduces Linus' friend and classmate Janice. Though this is the first (and only) time we see her, it's implied they've been friends for a long time.
• Pinky and the Brain: The show parodies this trope when a new character, Larry, is given the "Remember the New Guy" treatment by Pinky and the Brain. It starts with the theme song, in which Larry shoehorns himself in at the end of each line, setting the tone for the rest of the episode. The network, for whatever reason, demanded that a third character be added to the main lineup, so the writers created Larry, a character who added absolutely nothing to the formula and obnoxiously inserts himself into both the gags and even the show's theme song, for a single episode. At the end of the episode, Brain realizes that they don't actually need Larry for their plans, so Larry decides to start a new career as a folk singer and form a duo with Paul Simon, changing his name to "Art" in the process. Larry is then for the end segment immediately replaced with yet another new character in similar vein named Zeppo, who obnoxiously inserts himself into the credits song. The episode was created as a protest to adding a third character, and to try and show a third character would destroy the chemistry. The network eventually did get Elmyra as their third character, which pretty much killed the series entirely.
  Gordon Bressack: To set the record straight: Charlie Howell and I wrote this episode as a protest to the network who were talking about adding characters to the show. We wanted to show that adding a character would destroy the chemistry between Pinky and Brain. That's why Larry is always in the way, is an afterthought every time Brain talks, and is absolutely no help in the plan, and Brain is such a genius that even in this alternate reality he knows there shouldn't be a Larry.
• The Powerpuff Girls (2016) introduces a new Powerpuff Girl named "Bliss" during the second season. No, she's not a recently created character like Bunny was. She's a Long-Lost Relative that was created ten years prior to the Powerpuff Girls. According to her backstory, the Professor had a rivalry with another professor who created the perfect little boy. Utonium tried to one-up her by creating the perfect little girl but his original creation involving Chemical W wasn't perfect enough. Bliss would lose control of her powers whenever upset or scared. One day Bliss vanished during one of her episodes and was presumed dead until she reappeared ten years later. This all goes against the original show and the established backstory of the girls. The girls are the first known Artificial Humans and Professor Utonium had no parenting experience prior to their creation.
• Rainbow Brite just randomly had Moon Glow and Tickled Pink appear one episode without any explanation. Everyone acts like they've always been around.
• The third season of The Real Ghostbusters introduced three children who were chummy with the Ghostbusters known as the Junior Ghostbusters. They first appear in "The Boogieman is Back", where they are treated as if they've always been recurring characters on the show.
• Specky from ReBoot. Between the final scene of season two and the beginning of season three (both showing the same characters in the Principal Office control room), he's suddenly in the room with them as the main computer guy, and there seems to be an unspoken implication he was there all along.
• Somewhat parodied in the episode of The Replacements that introduced Abby's younger sister Tiffany. Abby says something along the lines of: "As you all know, my little sister Tiffany has been to boarding school for the past few years." Only for the Daring family to reply: "We didn't know that."
• Rick and Morty:
  • Parodied and subverted in the episode "Total Rickall". It begins with an apparent uncle of the Smith family treated like he's always been a part of the cast, but it turns out he's the first of many shapeshifting alien parasites who have implanted false memories of being lifelong close friends. In a darkly comic Double Subversion, exactly one of those new characters (Mr. Poopybutthole) fails to change back after being shot, showing he was Real After All.
  • Also parodied in the episode "Mort Dinner Rick Andre", where Rick's arch-nemesis Mr. Nimbus is introduced. Neither the viewers nor Rick's family had ever heard about him until then. (though apparently the writers had planned to introduce him before, it just never happened for one reason or another)
  • The C.H.U.D.s, humanoid horses from the infamous episode "Rickdependence Spray", live in a medieval-style society under Earth's crust, are said to be a menace for humans, and Rick has a history with them. They have never been mentioned before.
• In the second season of Rocket Power, a new member of Lars' gang, named Animal, is added to the crew, yet he's treated as if he was always along with the gang.
• Rocko's Modern Life:
  • A flashback in "Down the Hatch" has a pink bunny inexplicably hanging around Heffer and Rocko. Heffer doesn't know who the bunny is and asks about it.
  • Subverted during the episode "The Big Answer". Rocko and Heffer drag Filburt off to a bachelor party the night before his wedding accompanied by a rabbit and a weasel(?). At some point during the party, Filburt whispers to Rocko, "Who are those guys?"
• Sheep in the Big City poked fun at this. When General Specific's cousin General Lee Outrageous made his first appearance, it started with Private Public telling General Specific about his cousin calling, to which General Specific asked if it was the same cousin with whom he had a rivalry that he never mentioned before.
• The Simpsons:
  • Played for Laughs in "The Itchy & Scratchy & Poochie Show" where the family discusses the new addition of Poochie the Dog on The Itchy & Scratchy Show. During this discussion, a teenage roommate of the family named Roy, who never appeared before but wasn't treated as a newcomer, suddenly shows up:
    Lisa: Adding a new character is often a desperate attempt to boost low ratings.
    Roy: Yo, yo! How's it hanging, everybody?
    Marge: Morning, Roy.
    Homer: (very blasé) Yeah, hiya Roy.
    • Roy then gets Put on a Bus in what sounds like a pitch for a stereotypical sitcom near the end of the very same episode:
      Bart: I guess people just weren't ready for Poochie. Maybe in a few years.
      Roy: (carrying a suitcase and a letter) Good news, everybody! I'm moving into my own apartment with two sexy ladies!
      Marge: Oh, then I guess this is good-bye, Roy. Maybe we'll see you in a few years. (kisses him goodbye)
  • The season 25 episode "Four Regrettings and a Funeral" featured the funeral of beloved character Chip Davis (in reality the character never existed). Originally the episode ended with a montage of images from classic Simpsons episodes with Chip inserted into them (including Chip as the fifth member of the B-Sharps, Chip in the Plow King commercial with Barney and Linda Ronstadt, and Chip in The Simpsons Movie's "bountiful penis" scene sitting next to Ned). It was supposed to run during the end credits but it was removed for the broadcast version and replaced with an "In Loving Memory" card for the recently departed Marcia Wallace. The original credits featuring Chip can still be viewed on Hulu and YouTube.
• In Sonic the Hedgehog (SatAM), Dulcy the Dragon just suddenly appears in the second season premiere as if she was one of the Freedom Fighters the whole time. Semi-justified in that there appeared to be a Time Skip between seasons 1 and 2, so it's likely that she joined up during that time frame.
• South Park:
  • "Quest for Ratings" features the guys running a news show on the elementary school closed circuit television system and they act as though they've always done this and it's never mentioned again.
  • In the early seasons, Kenny's family consisted of his parents and an older brother; then, in season 9's "Best Friends Forever", there's suddenly a little girl hanging around them. It's not until five seasons later, in "The Poor Kid", that she is confirmed to be his younger sister Karen, whom he's very protective of. For what it's worth, earlier press releases/scripts mentioned Kenny having a sister, but it's odd that so many episodes with the McCormick family never showed her before the ninth season.
  • Celebrity example: "200" was a Continuity Cavalcade where every celebrity ever wronged by South Park joined forces to sue the town. Among them was Tim Burton, never even mentioned in previous episodes. Tim Burton was written into this episode to be mocked. He has thus become the 200th celebrity to be victimised by the town of South Park.
  • Parodied in "Red Man's Greed", when a random kid with "ALEX" written on his shirt appears in multiple scenes, each time giving a generic line that any other character could have said. It takes until the very end of the episode for anyone to comment on it:
    Stan: Dude, who the hell are you?!
    Alex: Alex. Alex Glick. I got to come on and do the guest voice thingy.
    Kyle: What?! Get the hell out of here!
    Alex: (exiting) Hi Mom! Hi Dad! Hi Jill!
  • Wing, from the episode of the same name, and based on the real-life singer of the same name, is said to be Tuong Lu Kim (the City Wok owner)'s wife. She never appeared in any other episodes before or since, except for a brief cameo many years later in "Cock Magic", though. However Tuong Lu Kim is actually the fake identity of a Caucasian man, Dr. Janus so it kind of makes sense to not have her around.
  • "Sons a Witches" from season 21 is centered on a Halloween tradition of the South Park adult males, drinking and smoking crack while dressed as witches, which in itself has never been mentioned before. One of the participants, Chip Duncan, is a new character who nonetheless is implied to do this every year and to be disliked by the others. He's also an example of We Hardly Knew Ye since he turns into an actual witch and the President destroys him with a Kill Sat.
• SpongeBob SquarePants: "Goons on the Moon" shows us Sandy's "Science Scouts" troop: SpongeBob, Pearl, and... Squidina, a character who we have never seen before, but gets treated just like anyone else. She gets a random reappearance in "The Goofy Newbie" a season later, but goes on to be the Deuteragonist of The Patrick Star Show.
• In Star vs. the Forces of Evil episode "Cheer Up Star", Star notices that her enemy Ludo has some new monsters in addition to the recurring Mooks he brings along. Ludo, however, asserts that the new monsters were always there in previous attacks.
• Steven Universe:
  • Though Steven never met Onion's mother Vidalia before the audience did, she'd been friends with Greg and Amethyst for over a decade. While Amethyst hadn't talked to her in years, Greg had apparently kept in touch but never mentioned her (to the audience or Steven) outside of one flashback.
  • Bismuth from the episode of the same name. Garnet and Pearl are utterly ecstatic to see her and appear to have been close friends with her. Meanwhile, neither Amethyst (born a few centuries after the show's Great Offscreen War) nor Steven know anything about her, as Garnet and Pearl never mentioned her, and Rose Quartz never left anything behind that mentioned past members of the team. When they're alone, Amethyst and Steven even talk about how weird it was that Garnet and Pearl never discussed this with them, with Steven reasoning that they prefer not to talk about the war. It turns out that Rose Quartz had a good reason to never mention her...
  • Spinel, the villain of the movie, has some history with Pearl, but the movie is the first time the other Crystal Gems learned of her existence. This is connected to both Pearl's history as Pink Diamond's servant, which she was forbidden to speak of until late in season 5, and the implication that Spinel had been forgotten by pretty much everyone who knew about her before she arrived on Earth. Spinel is pissed when she finds out this trope is in effect.
• Sushi Pack has a tendency to do this for villains. Oleander, Sir Darkly, and Paradoxtor were all introduced as villains that appeared before (Sir Darkly even had a quick recap flashback), despite never having proper introductory episodes.
• Team Umizoomi:
  • Bot immediately recognizes The Trouble Makers in the Season 4 premiere "The Boy with the Dragon Skateboard", despite said premiere being the debut of the latter.
  • Likewise, inverted. Any character/villain recently introduced in certain episodes/specials, if Team Umizoomi doesn't introduce themselves beforehand, will address Team Umizoomi by their actual name, even if it's never given it out to said character/villain.
    • One example of this inversion is "Umi Cops!", where the Team is called upon by the Police General as The Umi Cops, despite only becoming cops recently.
• Teenage Mutant Ninja Turtles (1987):
  • The episode "Night of the Rogues" had Antrax and Scumbug. Both of them already had toys, but they had never been mentioned in the show proper before that episode.
  • In the episode "White belt, Black Heart" Splinter apparently had a human pupil named Yoku, who we have never seen before, and yet the Turtles all knew him and remember their time with him and how he walked out on Splinter.
• Teenage Mutant Ninja Turtles (2012): In the episode "City At War" we meet Karai's best friend Shinigami, who is also a fighter and has been Karai's close friend since childhood. There was no sign of Karai having any friends before this, nor did Shinigami fight against the Turtles with Karai before the latter's Heel–Face Turn even though she apparently had a strong ally around all this time.
• When ThunderCats (1985) began, there were only three mutants: Ssslythe, Monkian, and Jackalman. However, later episodes randomly added a fourth mutant, Vultureman, who had never even been mentioned before.
• Both The Transformers and G.I. Joe: A Real American Hero had this in spades. Due to the toyetic nature of these cartoons, new characters from the most recent product releases would frequently be written in at the behest of Hasbro, sometimes even getting their own spotlight episodes. The writers rarely bothered to explain why we'd never seen these characters before, especially when they possessed special abilities that would have saved the day in earlier episodes.
  • The cast all but doubles in Transformers season two due to never-before-seen characters who are treated as having been there all along. In fact, one story depends on them having come to Earth at the same time as the others — everyone is affected by "cybertonium" deficiency due to having been away from Cybertron for so long, which rules out anything like having been on Cybertron during Season 1.
  • A bit more believable with G.I. Joe, as it can be — and has been, in some cases — handwaved as them being new recruits. Alternatively, that they just weren't on duty during past episodes.
• In Wonder Pets!, the Origins Episode "How it All Began!" shows that Ollie the Bunny was the very first animal that the Wonder Pets helped when they first got together, completely ignoring the fact that Ollie only appeared for the first time later in the show's run.

---