Throw It In / Western Animation

• The Simpsons:
  • The often-quoted sung line: "I am so smart! I am so smart! S-M-R-T! I mean, S-M-A-R-T!" This was an actual mistake by voice actor Dan Castellaneta, but it was just so "Homer" they left it in. Misspelling Songs have since become a feature in the series.
  • In "Grade School Confidential", Homer is using a megaphone to talk to Bart (who is on the roof of the school) to ask him where their TV remote is. Bart shouts forto him to check his pocket. He does and finds the remote, and then tells Marge and Lisa, who are standing right next to him, that it was in his pocket through the megaphone by mistake. "IT WAS IN MY- (puts megaphone down) It was in my pocket." This was a mistake by Castellaneta while using a real megaphone during recording; he tried to correct it, but the writers thought it was so in-character for Homer that they kept it in.
  • Homer's famous "D'oh!" was improvised by Castellaneta. The script only said "annoyed grunt" (and still does). It was originally a Laurel and Hardy reference (James Finlayson would occasionally let out a pained "D'ooooooooooh"), but Castellaneta was told to shorten it the first time he used it.
  • Homer's song "Dancing Away My Hunger Pangs" in the season 12 episode "Hungry, Hungry Homer" (where Homer goes on a hunger strike to save the town's baseball team) was ad-libbed by Dan Castellaneta.
  • Recurring guest star Albert Brooks ad-libs a lot. This is notable when he plays Hank Scorpio in "You Only Move Twice" - most of his fast, random declarations are improvised. The entire "hammock district" bit is an ad-lib — hence why Homer only replies with a quick "yes", because even Dan Castellaneta had trouble keeping up with Brooks. Only at the end does he catch up and reply, "Oh, in the hammock district".
  • The creators accidentally gave two characters the last name "Wiggum" — Clancy, the town's idiotic police chief, and Ralph, Lisa's unintelligent classmate. They realized that both characters were dumb and chubby, and decided to make them father and son.
  • Humberto Vélez, Homer's original Latin Spanish voice actor, came up with the dub's translation of the "Sweet merciful crap!" line in "Summer of 4 Ft. 2". It was translated as "¡Me quiero volver chango!" ("I want to go back to being a monkey!"), a phrase his friend would often say.
• Adventure Time: When Adam Muto pitched the episode "What Was Missing", he misspoke, which is the reason why Finn says, "I'll get your kid back toy". The team thought it was funny and kept the flub for the actual episode.
• Beast Wars:
  • Megatron's famous "Yeeeeeeeessss..." wasn't originally scripted, but was improvised by voice actor David Kaye, who thought it fit the character. It quickly became his Character Catchphrase.
  • David also coughed while recording one of Megatron's power-hungry Evil Laughs, but they decided to leave it in, with the animators adding a Reaction Shot of a surprised Inferno to complete the effect.
• Futurama:
  • An In-Universe example is where Calculon shows a clip of a new episode of his show, where he does a Big "NO!". He informs the talk show host he was actually supposed to say "yes!", but "gave it a little twist".
  • Fry's "No I'm... doesn't?" from "The Route of All Evil", in response to being told that alcohol makes one stupid. The line was intended to be spoken normally, but Billy West was confused by the grammar, creating the famous stammered delivery, and it was so fitting that they kept it in.
  • The Hypnotoad's signature loud buzzing was originally just a placeholder while the sound effects department came up with a better sound. However, test audiences found the placeholder noise so unsettling and fitting that they kept it in.
• Hey Arnold!: When somebody accidentally drew a very Off-Model version of Arnold, they decided to make him an actual character — Arnold's Country Cousin Arnie, who has two episodes centered around him.
• Invader Zim:
  • The first episode contains the line "Invader's blood marches through my veins - like giant, radioactive rubber pants! The pants command me! DO NOT IGNORE MY VEINS!" The line was supposed to say 'ants'. But it's the kind of Gag Series where "pants" actually fits better.
  • The episode "Walk of Doom" has a shot where a police officer walks past the camera. He was drawn a little too big on the first take, so they sent it back to be redone... only for the new take to have him become even bigger. At that point, they just accepted it, adding booming footsteps and monstrous laughter to enhance the effect.
  • "Hamstergeddon" features Ultra Peepi swaggering down the street, not by intention. It came back from animation that way, and Jhonen loved it and had the composer make funk music to go under it. "I want to hear Barry White saying 'Ultra Peepi'." Check it out here.
  • In the original script for the scene in "Mortos der Soulstealer" where Zim and Dib yell at each other across an intersection, the street between the two was supposed to be filled with vehicles driving by — hence why the two have to yell back and forth, in order to be heard over the traffic. When the animation got back from the studio, the crew was bemused to find that the animators had forgotten to put in the traffic. However, upon reviewing the footage with the dialogue, they found that the awkwardness of the two shouting over nonexistent traffic was hilarious, and kept it as it was.
• In Batman: The Animated Series, The Joker's excited little squeal after explaining his plot to Batman in the episode "Joker's Wild" wasn't scriptes. Mark Hamill just sort of did it after reading his line, and the cast and crew were laughing so hard that they apparently took the rest of the day off. The next day, they went ahead and added an extra second of animation to include it.
• According to Bruce Timm, Terry's revelation as Bruce's biological son in Batman Beyond and the Justice League Unlimited episode "Epilogue" stemmed from the earlier realization that, with his established redhead and light-brunette parents, Terry and his younger brother's black hair was genetically implausible. Apparently, nobody uses hair dye in the future.
  • In "Injustice For All", a Justice League episode, Solomon Grundy carries off Cheetah, and it was supposed to be implied that he murdered her... only she ended up being carried to jail along with the other members of the Injustice Gang. From that, they just said that she was alive, and she went on to appear in Unlimited.
• Kim Possible:
  • Shego was originally created as a generic, stoic Dragon to Dr. Drakken. After the creators heard Nicole Sullivan's performance, though, they gave her a bigger role, making her sarcastic, more competent, and far savvier than Drakken. Today, she's one of the show's most iconic characters.
  • Motor Ed was created because John DiMaggio was goofing around in the break room and made up the voice for a laugh.
• Freakazoid!:
  • Freakzoid voice actor was supposed to refuse a literal plot hook with just a simple "No." The sequence ended up twenty seconds longer because of voice actor Paul Rugg adding a tiny bit more.
  Jeepers: Hehehehehe...you want to see something strange and mystical?
  Freakazoid: NO! Get out of here with that watch! Lay off the poor beavers, will ya?! SHEEEEESH! You're a creep! Go away! We were having a good time until you showed up, Jeepers! Urrrg! Go have some coffee with cream or something! Because I'll tell you something...this is a happy place!
  • According to the audio commentaries, this happened a lot. Even the casting of writer Paul Rugg as Freakazoid was an accident. He was just supposed to be the placeholder, but ended up being so funny (in part because of his wild improvisational skills), that he was cast permanently. Apparently, several large sections of the first episode were entirely made up on the spot by Rugg.
  • Paul Rugg's famous "Low Bridge" chant was also meant to be a placeholder, but was apparently so utterly perfect and so "Freakazoid" that they just kept it in - much to Rugg's chagrin.
• Looney Tunes:
  • Bob Clampett's 1943 short An Itch in Time has a scene of a dog, having been irritated by a flea, scooting wildly around a carpet on its rear end. As an "inside" joke, Clampett and his animators added an off-color gag of the dog pausing to tell the audience, "Hey, I'd better cut this out -- I may get to likin' it!" fully expecting that either the studio or the Hays Office would have it removed. Astonishingly, they didn't. This was apparently par for the course — they'd include intentionally inappropriate content to distract the Hays Office so the stuff they really wanted in would scoot by, only for the Hays Office to ignore the decoys and go for the real meat anyway.
  • What's Opera, Doc?: "SMOOOOOOOOOOOOOOOOGGGGGGGGGG!"
  • Happens in-universe in Porky's Duck Hunt, the cartoon which spawned Daffy Duck. In a real-life example, the duck was never intended to be anything more than a one-off gag, and he was retroactively named "Daffy" when he proved to be extremely popular.
    (Porky sends his dog after a duck, but instead of letting himself get caught, the duck picks up the dog and dumps him on the shore of the pond)
    Porky: Hey! Th-th-that wasn't in the script!
    Daffy: Don't let it worry ya, skipper. I'm just a crazy darn fool duck. (bounces away across the pond, laughing maniacally)
  • A meta example occurred with Bugs Bunny during his redesign for "A Wild Hare". A friend of Mel Blanc saw a drawing of Bugs Bunny, and said "Tough little stinker, ain't he?" This inspired Mel Blanc to give Bugs Bunny a Brooklyn/Bronx accent.
• Wander over Yonder:
  • In "The Buddies", Hater's utterances "Something, something, something" during the "Best Friends Forever" song were originally a placeholder, but the crew loved it so much they decided to keep it in.
  • Something the So-and-So's long-winded goad over what to do with the ring in "The Battle Royale" was added last-minute, due to the episode coming in a minute short during production.
• The Woody Woodpecker short Wet Blanket Policy originally didn't have "The Woody Woodpecker Song" in it, but it was added in at the last minute by Walter Lantz, when he discovered how much of a surprise hit the single had become.
• The episode "Shrabster" of Sealab 2021 involves a hammy, over the top announcer declaring "Indeed!" along with a linking remark with each scene change. The hamminess ultimately becomes too much for the announcer when leaving a clip involving a starving 14-year-old African boy.
  Announcer: Dead African child indee-hee-hee-hee-heed...(uncontainable laughter), I'm sorry. It's just so f-bleep-ing awful.
• Avatar: The Last Airbender:
  • Sokka was originally intended as a more laid-back character who was only subtly sarcastic. However, his voice actor, Jack DeSena, was a Jim Carrey-inspired comedian, so Sokka gradually turned into a much more over-the-top comic relief. The creators noted that because of this change, Toph ended up filling Sokka's original role.
  • What's known in the Avatar fandom as The Foamy Mouth Guy was a background character who was just supposed to faint after getting some good news. Then an animator got really creative, causing the guy to get so excited and animated that he foams at the mouth before passing out. The showrunners kept it in because it was much funnier than the original shot.
  • Haru's sexyfine 'stache came about because a bored animator snuck it in.
  • The show's staple Mix-and-Match Critters were also the result of a particularly bored animator.
  • An in-universe case when the Gaang watches a play about themselves, and Sokka goes up to the actor playing him and suggests a few lines and jokes. The actor promptly starts incorporating these suggestions into his performance, forcing the other actors to adjust to these unscripted lines on the fly. The actor playing Toph is visibly confused the first time he does it.
• Sequel Series The Legend of Korra has a scene in "The Spirit of Competition" where Mako angrily storms through a door and completely ignores a fan trying to say hi ("Hey Makooooo-oh"). This originated when someone drew a random extra standing next to Mako in the animatic, and the episode's director thought he looked disappointed.
  • There's an In-Universe case in a mover, where Bolin kisses an actress in a scene where he isn't supposed to and the director decides to keep the kiss.
• In the Code Lyoko episode "Tidal Wave", Odd's final line, "I'm so hungryyyyy!", was ad-libbed by his dub actor.
• In the Daniel and the Lions' Den segment of the first VeggieTales, a render glitch caused a sudden flash of light in the background during the wise men's song with King Darius, where they tell him that anyone who doesn't swear ultimate loyalty to him under their new law will be executed. The animators weren't able to fix it, but they felt it darkened the mood in the right way, so they synced it to the sound of Dramatic Thunder.
• My Little Pony: Friendship Is Magic:
  • In the first episode, a pony in the background was given crossed eyes as a joke by an animator. She wasn't intended to be visible, but some last-minute blocking changes moved a bunch of other characters out of the way, leaving her goofy expression in full view. Fans immediately noticed and were amused, leading to the pony being nicknamed "Derpy Hooves". The joke became so famous that the show's creator, Lauren Faust, said, "She can be Derpy if everyone likes." They also gave her the cross-eyed look in most other episodes she appeared in during season 1, and from season 2 on her appearances are fully scripted. She has since gone on to become one of the most beloved characters in the series, and something of a mascot for the fanbase, with the largest MLP image booru on the net being named after her.
  • As can be gleaned by its realistically unpracticed and stumbling delivery, the Cloudsdale anthem as performed by Spike in "Equestria Games" was genuine improvisation on Cathy Weseluck's part.
  • In "Pinkie Apple Pie", Michelle Creber was told to improvise a rap song for Apple Bloom when she found the map. She chose to perform a variation on the "Ponylicious" meme, unprompted.
  • The episode "Stranger than Fan Fiction" features Quibble Pants giving a monologue over the credits about the next Daring Do book. Patton Oswalt, who voiced the character, improvised the whole thing.
  • Rarity calling Sweetie Belle "Repeatie Belle" in "Marks for Effort" was improvised by Tabitha St. Germain.
• Ren & Stimpy "Adult Party Cartoon":
  • One example ultimately led to cancellation of the series. The episode "Onward and Upward" contains a graphic homosexual sex scene between the eponymous duo, added as a joke by an animator. Creator John Kricfalusi explained that there was never supposed to be any actual sex in it, and that suspicious dialogue aside, Ren and Stimpy were supposed to be playing baseball under the sheets (as a part of a vague "pitcher and catcher" metaphor earlier in the episode). He claimed he wanted to cut it straight away, but he felt sorry for the animator, who thought it was funny. The scene was left in and caused a minor uproar at an animation newsgroup, where a group of people thought Kricfalusi was trying to sabotage his own show - the executives at Spike TV saw this conversation, thought that was how everyone felt, and cancelled the project
  • The animation error in Stimpy's eyes (he's drawn with Black Bead Eyes for a split-second, making him look like Barney Rubble) in "Stimpy's Breakfast Tips" was so hilarious that John left in in.
• TUGS:
  • When building the models, it was found that Zorran's eye mechanism caused the front of his hat to tip up. They left it in because they thought it added to the expressiveness of the character.
  • In the episode Munitions, a piece of debris from one of the explosions hits Warrior, bouncing off of him. A piece of dialogue was later added with him exclaiming "That bit hit me!"
• Star Wars: The Clone Wars: According to Ashley Eckstein, she was asked to use an Icelandic accent for the voice of Ahsoka Tano. However, when she came in with a practiced Icelandic accent, it apparently wasn't what they expected. The voice she ended up getting told to do in the show is based on the tones in her real voice during the audition when she was frustrated that she couldn't figure out what accent they wanted.
• In The Brak Show, Dad was originally intended to be around the same height of the rest of the main cast. A mistake in scale was made while compositing a scene, and the new, comically small version of the character was deemed funny enough that they stuck with that design.
• Home Movies is so improvised, you can hear the actors stuttering and trying to come up with a new line. The show's creators have noted that some fans were upset to find that the show was even loosely scripted—having plot points outlined, but leaving most dialogue to the actors.
• The Angry Beavers: Nick Bakay and Richard Steven Horvitz, respectively the voice actors for Norbert and Daggett, improvised a lot of their dialogue together.
• In the first episode of The Flintstones the script originally called for Fred to yell "Yahoo!", but voice actor Alan Reed thought that was too bland and asked if he could come up with something better. This is how he came up with the catchphrase "Yabba-dabba-doo!", as a play on the Brylcreem hair cream slogan "A little dab'll do ya!"
• Reportedly, during the first table reading for Scooby-Doo, Where Are You!, Velma's voice actress Nicole Jaffe dropped her glasses and exclaimed, "My glasses! I can't see without my glasses!" The writers liked the line so much, and thought it was so in-character for Velma, that they turned it into a Running Gag/Character Catchphrase for her.[[note]]Curiously, she doesn't say it in the first episode. After Scooby knocks her down and her glasses come off, she says "Now look what that dog did. He knows I can't see without my glasses!"[[/note]
• SpongeBob SquarePants:
  • Tom Kenny actually had a cold during production of "Suds." If you listen closely, his recordings sound quite genuine.
  • In "House Sittin' for Sandy", SpongeBob spends the whole first half of the episode in Sandy's treedome without a water helmet, until Patrick arrives and reminds him he needs one. This was because halfway into production, the crew realized that they forgot to put a water helmet on SpongeBob; rather than fix it, they kept it in, and Patrick was added to the episode to give SpongeBob the water helmet.
• In Star Trek: Lower Decks, Tawny Newsome threw the line "Move, Jennifer!" into a scene where Mariner is pushing past people. She wasn't privy to the animation, though, which is why there's canonically an Andorian named "Jennifer" in the crew.
• Young Justice (2010):
  • In the episode "War", Robin and Impulse's fist bump was thrown in by the storyboard artist, who was a fan of their friendship in the comics.
  • In "Coldhearted," we briefly see two policemen talking. One of them was supposed to be a woman, but the art came back with two men. Cree Summer had already recorded the line for one, so they just altered the pitch and used it anyway.
• Phineas and Ferb:
  • While the show overall contains very few ad libs, one notable one appears during the song "Only Trying to Help" from the episode "Phineas and Ferb: Mission Marvel". The end of the song, where Isabella and Candace repeat a line of the chorus, was originally improvised by Isabella's voice actress, Alyson Stoner.
  • In the original version of the episode, when Iron Man got Thor's powers, he would be seen carrying the hammer. When Dan Povenmire and Swampy Marsh asked the execs at Marvel about it, they told them that "wielding Mjolnir was about worthiness, not power" — but then asked about the flying and lightning, and they told them that only worked with the hammer. So they put in the whole conversation between Iron Man and Thor about how Mjolnir works.
• Two episodes of Rick and Morty ("Rixty Minutes" and "Interdimensional Cable II") revolve around Rick and Morty watching interdimensional TV. The scripts for the actual TV segments are largely improvised, and a lot of awkward deliveries, stumbling over words or just cracking up at the end of a scene are left in (presumably because they're funnier that way.) This is quickly lampshaded when the title characters point out how improvisational interdimensional TV feels.
• This happens quite a bit in Penn Zero: Part-Time Hero. According to co-creator Sam Levine, Thomas Middleditch (voice of Penn) and Larry Wilmore (voice of Larry) improvised some of their best lines.
• The Loud House':
  • The eponymous family owes their name to this trope. Chris Savino was exchanging emails with a friend who was helping him work out some of the kinks, and the friend asked if "Loud" was the family's surname; Savino replied "It is now!"
  • In the episode "Back Out There", Vanessa Marshall, who voices an old woman named Tina and the waitress, also voices a young girl named in the script as "young flustered girl" upon seeing the boys. She then started hiccupping during recording, which was then integrated into the episode due to still filling the same role, and the character was credited as "young hiccupping girl" .
• Subverted with Sonic Boom. One moment seems like Roger Craig Smith flubbing his line, but he's actually reading it exactly as scripted. He's that good.
  Sonic: Use this to build a- a bigger bag- baggit bo- build a begger- built it ba- buggy baggit- bagger box buzzard... (shakes head) The answer is simple, but saying it, not so much.
• In the original animation of Tigtone, Tigtone's voice actor Nils Frykdal descres a side quest to obtain magic boots as "treasureful" instead of "treacherous", which fit the character so perfectly that it was kept in the final cut.
• The Dexter's Laboratory episode "Chubby Cheese" has a sequence where the characters watch a performance by an animatronic band in the titular Suck E. Cheese's establishment. At the very end of the scene, some audience members inexplicably float into the air and fly off into the distance. This was an animation mistake that has had two explanations; one is that the animation department misinterpreted a storyboard where the audience all had their arms in the air as a superhero pose rather than cheering, the other is that they misunderstood a stage direction about the audience "taking off" (as in leaving). Regardless, this was left in the final product with an appropriate "flying away" sound effect added - it adds to what is already a pretty surreal scene.
• The original script for Winnie the Pooh and Tigger Too had Tigger simply saying "goodbye", but Paul Winchell's third wife, Jean Freeman, suggested he ad lib "T.T.F.N. — ta-ta for now!" which soon became an iconic Character Catchphrase for Tigger.
• South Park
  • The Crab People from "South Park is Gay!" were originally just a placeholder Trey Parker and Matt Stone were using until they figured out the actual plot for act three, but then just ran with it when they couldn't come up with anything else. For what it's worth, later episodes have used "Crab People" as a stand-in for a really stupid idea.
  • In-Universe example: In "A Very Crappy Christmas," the boys are making a Christmas film. It's supposed to be wholesome, but naturally, Kyle and Cartman get into a fight while recording and start screaming insults and profanity at each other.
    Sound man: The script. It's sweet.
    Stan: That's not in the script. They do this all the time.
    Sound man: Well, it should be in the script. All that "you're fat" and "you're a Jew" and stuff. It's great.
• According to We Bare Bears creator Daniel Chong, Ice Bear's voice actor Demitri Martin normally recorded lines by himself. As a result, this gave Martin a lot of freedom to ad-lib.
• Elena of Avalor: Craig Gerber has mentioned that some of the dialogue wasn't in the scripts and was improvised by voice actors. In particular, much of King Hector's dialogue was improvised by Jess Harnell due to still fitting his boisterous nature.
• Inspector Gadget: The first Greek Alternative Foreign Theme Song features some of the vocalists bursting into laughter and ad-libbing towards the end. This was left in the final recording.
• 12 oz. Mouse: The character Rhoda was first sketched on the back of a Perfect Hair Forever script, and several lines of dialog from the show could be seen inside him/her. The makers liked the look and kept it in the show.

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