The Adventures of Teddy Ruxpin: Grubby, on occasion. The Crystals reveal that honesty is one of his defining traits, but sometimes, he gets a bit insensitive. In one episode, Teddy sums this trope up nicely after an argument between Grubby and Gimmick: "Grubby was trying to be honest. But you don't have to be mean to be honest, Grubby."
In "The Words", Darwin temporarily becomes a brutally honest Jerkass after Gumball teaches him to speak his mind.
In the Animaniacs cartoon "Bumbie's Mom", Slappy used the "Have I ever lied to you?" line on her nephew Skippy. The boy proceeds to give a laundry list of his aunt's past fibs, such as keno being legal in Burbank.
Arthur: In "To Tibble the Truth", the Tibble twins become fearful and even have a Guilt-Induced Nightmare that they will be sentenced to prison for lying all the time after D.W. tells them that she wouldn't be surprised if they "ended up in jail someday", so they vow to speak nothing but the truth—and they end up taking it way too far, alienating everyone around them and even amongst themselves.
In "A Bullet for Bullock" Harvey Bullock asks for Batman's help to find out who is trying to kill him (Bullock doesn't want to get the department involved, lest they take too close a look at his rule-bending ways). He doesn't soften his disdain for Batman's vigilantism one bit; Batman simply tells him "I appreciate your honesty."
Also occurs in "Never Fear" with a Wayne Industries employee under the influence of Scarecrow's fear-killing gas. He promptly tells off his boss (Bruce Wayne) for intimidating him while announcing his immediate resignation, and then shamelessly and aggressively hits on one of Wayne's attractive lady secretaries on whom he's had a secret crush for years while security is escorting him out. In his ransom demand to the mayor, Scarecrow threatens to expose everyone else in the city to his gas as well, which, as Batman points out to Robin, means everyone in Gotham will be just as brutally honest as that former employee of his.
Inversion: In the episode "Ghost Writer In the Sky", Beetlejuice writes his life story which is full of lies about his Roadhouse neighbors. He leaves Lydia out of the book because he can't bring himself to say anything nice about anyone.
Boy Girl Dog Cat Mouse Cheese: "Nothing But the Truth" has Boy being fearful of telling the truth because he doesn't want to hurt other peoples' feelings, so Mouse and Cheese encourage him to be more honest—but his kind of honesty is far too blunt to bear.
C-Bear and Jamal: In "The Truth and Nothing But the Truth", Jamal lies in order to get a job on the school newspaper as an advice columnist. When he is no longer able to lie, he begins being too honest—even in his own home. After learning how much the truth can hurt, Jamal apologizes to the people he insulted.
Danger Mouse: Count Duckula's rendition of "Fangs For The Memories" is so laughably bad that even Penfold says so. Naturally the Count takes umbrage.
Doug: In "Doug's New Teacher", Doug is worried that the new substitute teacher thinks he is a troublemaker but Skeeter reassures him that she will probably forget about it the next day. When Doug asks his friend if he really thinks so, Skeeter admits he doesn't and only said that to make Doug feel better.
Played with in the Elefun and Friends short, "A Tangled Tale":
Giraffalaff: (to Elefun) Can you keep a secret? Froggio: Well... no. Giraffalaff: I wasn't whispering to you!
In Fat Albert and the Cosby Kids the kids are trying to figure out how to handle a classmate named Suede Simpson, who everyone tries to avoid because he never bathes. Fat Albert was elected to tell him but just couldn't break it to him. Finally, Russell flat out tells him he stinks and no one wants to be around him.
This is the subject of "Franklin's Homemade Cookies" on Franklin — Franklin is unflinchingly critically honest of Bear's craft project that he gives to him and then has to deal with the same thing when it turns out his cookies have way too much ginger in them.
Futurama: In the episode "The Devil's Hands Are Idle Playthings", Fry is forced to finish his complex opera with his incapable old human hands.
In the Goof Troop episode "Talent to the Max", Max is really bad at magic. When he asks for feedback, Pistol evades the question, Goofy delivers a non-answer, and PJ says he "stinks like a skunk with BO" and continues from there. Max takes everyone's comments as compliments, except PJ's, which he takes as a much milder criticism than it was meant to be. PJ spends the rest of the scene trying to convince Max he meant what he said.
Jimmy: You wouldn't want to crush my all-time number one dream, would you? Lucius: Yes, yes I would.
Johnny Test: In "Johnny Two Face", Johnny gets this after a string of lies. His sisters mutate him so he has a second mouth; the mouth soon takes control of him, then aggressively tells the truth to everyone. Everything it says is hurtful and leave the victims angry at Johnny — except for his sisters, who "conveniently forget" the remark he made about the fact that they are both chasing the same guy but can't both have him.
Pretty, being an Alpha Bitch, has no qualms with telling people what exactly is wrong with them (such as telling Kaeloo that she's fat, or Stumpy that he's stupid).
Kaeloo herself does this unintentionally sometimes. In Episode 136, when she truthfully told Pretty that her new bag was ugly and Stumpy that his drawing of Ursula was horrible, Stumpy actually started crying.
When Mr. Cat actually bothers to be honest, it tends to be the brutal kind of honesty. For example, when he gets invited to a dinner party by Kaeloo, the first thing he does is criticize the dining room's decor. He also tends to tell Stumpy to his face that he's ugly, stupid, and/or a loser.
The show's fifth season introduces us to Stumpy's little sisters, of whom two fit this trope. Vitamine is Innocently Insensitive and points out things like how Stumpy sucks at soccer. Cramoisie is a jerkass who labels Kaeloo and Mr. Cat "ugly and fat" and "a twisted narcissist" respectively.
Kim Possible: In "Rappin' Drakken", Dr. Drakken creates a Mind Control shampoo formula and tries to Take Over the World with it. His initial attempt fails because the shampoo label told people what the stuff did; not surprisingly, nobody bought it.
In the episode "The Coronation", after Prince Wu's meltdown, Mako tells him that while Kuvira may be a tyrant, Wu might not be that good of a ruler either. The prince actually agrees, saying that no one had ever talked to him like that before.
Also, Toph doesn't sugarcoat it when she tells Korra that her lingering problems are keeping her from fighting well.
In the Bugs Bunny cartoon "Hare Trigger," Yosemite Sam challenges Bugs to draw a gun, which he does — with pencil and sketchpad. Sam says he's capable with a pencil himself and proceeds to draw a gun on the pad. Bugs examines it carefully then says "It stinks!"
This is a common gag in My Little Pony: Friendship Is Magic. Rainbow Dash is the most frequent offender, but others include Fluttershy (when she's pressured into answering a question she'd rather avoid), Applejack (as an unfortunate consequence of her virtue of honesty, though that usually depends on who wrote the episode), Twilight Sparkle (out of sheer awkwardness), and even Spike (as the youngest of the major characters).
Applejack, being the Element of Honesty, when she bluntly acknowledges how selfishly Rarity acted in "Rarity Takes Manehattan". Lampshaded by Rainbow Dash:
Applejack: Yeah, you were pretty rotten. Rainbow Dash: Wow, Applejack. I know your thing is honesty, but come on!
Rainbow herself once responded to a reassuring "You're not a laughing stock" with "She kind of is".
What ultimately breaks the "Inspiration Manifestation" spell over Rarity when Spike finally tells her that her "improvements" aren't making things better for anypony. He also tells Twilight she looks awful at the end after she's spent the entire day cleaning up Rarity's mess.
In "Equestria Games", Rainbow Dash encourages the Ponyville teams to win the gold... except for her team, who she admits probably won't do as well.
This is also commonly used by Pinkie's sister Maud, who rarely makes much effort to mask what she thinks of something if asked, which can often make her seem insensitive, such as in "Rock Solid Friendship" when she bluntly mentions that the gems Rarity mines for her dresses are really common, driving Rarity to near tears.
Applejack gets brutal honesty thrown back in her face in "Honest Apple", when her own honest opinions drive everyone in Rarity's fashion showcase to quit when she outright calls fashion ridiculous. AJ doesn't understand why everypony's so upset because to her, it's "just" fashion and she's just giving her honest opinion. To show AJ how Honesty can be hurtful, Rarity decides to give her a taste of her own medicine by taking her to a pony who not only doesn't like apples but tells AJ to her face that she considers them vile and disgusting. Rarity sarcastically ask AJ why is she getting defense and told her that's just Strawberry's honest opinion. By having something she cares deeply about disparaged to her, Applejack realizes that she'd been doing the same thing when it came to the fashion show, and seeks to make amends.
In My Little Pony: Equestria Girls – Friendship Games, one of the Shadowbolts (The Psycho Rangers of the Humane Six) is Sugar Coat. She's Applejack's counterpart, where she has the blunt honesty without any tact. There's also a dash of Captain Obvious, as she feels she has to tell Twilight she's "really bad at this" after the girl fails at archery.
One episode of O'Grady revolves around how the weirdness forced people to blurt out the truth no matter how cruel.
The Powerpuff Girls: Buttercup tends not to mince words. If she has something to say, she'll say it. Take for example the episode "Odd Bubbles Out" where Bubbles is excited and Buttercup asks her why; Blossom says the former has been talking about it (a visit from her unicorn friend, Donny) for weeks, to which Buttercup responds that she usually just tunes Bubbles out.
Regular Show: In "Eggscellent", Rigby falls into a coma from an allergic reaction brought on by trying to eat a huge omelet for an eating challenge. At the hospital, Mordecai and Benson get into a fight, with Benson saying that Mordecai's "friend" is going to keep getting him in trouble. Mordecai retorts that Benson doesn't have any friends, and when Benson responds with saying he does, Mordecai says that the only reason anyone hangs out with him is that he's their boss.
In Samurai Jack episode XCVIII, Jack goes on a spiritual journey that involves doing a Tea Ceremony for a monk. The monk's estimation of the tea Jack made?
Pearl: Greg is... nice, Steven... but I doubt Rose would trust someone like him with such a powerful weapon. Amethyst: Your dad's kind of a mess, Steven.
She also gives it to herself in "Cat Fingers": Pearl blames her for Steven's predicament and later claims that the moral of the episode is never to listen to Amethyst. Both times Amethyst replies "That's fair."
Steven: Amethyst... am I the cruelest creature on the planet? Amethyst: Oh Steven, those are just words that people use to describe how they feel about you.
Also Garnet. When Jamie sent her a love letter, her idea of a reply was just a letter saying "No." When coaxed into adding more, she adds "The End. Forever, and even after that."
When the Crystal Gems are trying to rescue Greg from the Human Zoo, Sapphire (who can see the future) comes up with a plan wherein they all pretend to adhere to their assigned roles (e.g. She's an aristocrat, Ruby is her bodyguard, Pearl is her servant, etc.). Followed immediately by this exchange:
Pearl: "Is this really going to work?"
Sapphire: "No."
In an early episode of Tangled: The Series, Rapunzel is ignorant of what it means to be booed by someone, so Cassandra explains:
Cassandra: It means someone hates you.
Eugene: Way to candy coat it, Cass.
In an episode of Tiny Toon Adventures, Hamton always gets Picked Last for soccer games. Plucky says it's not because they don't like him, but rather because he's "a lousy goalie".
In Trollz a stone ogre hates liars and only accepts the truth, even when it's negative. She asks the trolls if she's ugly, to which Amethyst agrees, but when Mica lies and says she's gorgeous she flies into a rage and attacks him.
In VeggieTales, one of the Silly Songs with Larry features Larry looking for his hairbrush. When Junior hears Larry wondering over his missing hairbrush, he has this to say about it:
Junior: Why do you need a hairbrush? You don't have any hair!
Nobody, even the announcer, on Wacky Races hides their disdain for the villain, Dick Dastardly. He even deflects it in an episode of the spinoff:
Announcer: As Yankee Doodle Pigeon breaks the morning stillness while flying another dangerous mission, he keeps a wary eye out for the villainous Vulture Squadron. Skippered by the deadly, diabolical, despicable demon of the skyways, Dick Dastardly. Dastardly: You left out dashing and debonair! (evil laugh)
Xavier Riddle and the Secret Museum: Although Yadina is very extroverted (not a wallflower at all), she is only six-years-old. This means that she can be very honest with just about anyone, and sometimes even blunt. For example, Yadina dislikes meanness of any kind, and she will let anyone who is not being friendly to another, know exactly what she thinks of their behavior.
