YMMV / OK K.O.! Let's Be Heroes

• Abandon Shipping: After "Big Reveal" aired, some fans whom shipped K.O. with Fink bailed out, as people debate whether or not it constitutes incest since Fink is basically Venomous' adopted daughter while K.O. is his biological son. Some fans do go full Incest Yay Shipping however.
• Accidental Innuendo: "T.K.O.'s House", On discussing letting TKO take over control to investigate the Glorb tree, demonstrating the importance of good word choice:
  TKO: [after pinning KO down on the ground] Let me do it. [grins, in slightly deeper voice] It's my turn to have fun.
  KO: Nuh uh, TKO. You're too naughty.
  TKO: Naurgh! You never let me do anything!
• Adorkable:
  • K.O. is an upbeat, sweet and dorky kid that loves heroes and is nice to everybody, even his super-deformed faces in jokes are also cute.
    Carol: You're as cute as I ever was!
  • Dendy is a nerdy, kindhearted introvert who's still developing her social skills, so a lot of her behavior comes across as cutely dorky.
  • K.O. clearly gets his behavior from the upbeat and energetic Carol, especially when she begins dating Gar and she really wants to do something nice because of everything he is doing for her.
  • Mr. Gar occasionally slips into endearingly awkward behavior when Carol is in close proximity. He definitely was this back during his days as El Bow.
  • Whenever he's around Professor Venomous during the early stages of their relationship (throughout the first two seasons), Boxman comes across as flustered, eager to please, and openly physically affectionate. His second party outfit◊ in "Villains Night Out" is a Totally Radical skater-esque getup which looks silly, but is also very cute.
  • When not on the job, Ernesto is a nervous, sometimes shy dork who fumbles around a lot.
  • Shannon acts like a brat most of the time, but once she gets a nice circuit in her body (such as when struck by lightning), she becomes much more endearingly awkward, without losing her usual intensity.
• Alternative Character Interpretation:
  • Red Action's opinion on her old team, the Hue Troop. She has a negative view on them, calling them dweebs and clowns, saying they do cheesy poses, their helmets are weird, and they take orders from a rock. While Enid thinks what Red used to do is incredible, Red sees it as an Old Shame. When she and Enid has to fight them, she doesn't even feel bad about hurting them. Even after her team forgives her and Red apologizes to them, she chooses to stay in 201X instead of returning to 301X with them. Did this negative view develop after she deserted her team and ran away to 201X, or did she always feel this way, even when she was still apart of the team?
  • Sort of a meta version: was Congress Woman written as over-the-top and preachy about serving justice in Boxman Crashes as a way of poking fun at the poorly received episode she debuted in, or was she merely written like that because the episode was from the villain's point of view, therefore making it make more sense for her to come off less likable?
  • Boxman stalling his announcement in "Stop Attacking the Plaza!"—was he trying to wait out the clock by drawing out his announcement until his 24 hours were up? Or was it just too physically painful for him to say easily?
• Alternate Self Shipping: Some fanworks ship KO with his alter ego TKO. While the two are able to interact inside of their shared mindscape in canon, fanworks sometimes skip this and depict them as having somehow gained separate bodies or simply being entirely different people.
• Angst? What Angst?: K.O. is put through the wringer throughout the series, especially with his early Butt-Monkey status. But despite all of this, he is still the same chipper Kid Hero ready to give a hand. By "TKO", this becomes a major part of the story as well as deconstructed. T.K.O., his Superpowered Evil Side, isn't just a new power, it is the representation of all of his repressed rage and fury over every slight ever committed against him. Not even his best friends and coworkers, Rad and Enid or even his own mother are exempt from this between the former's case of teasing him (even if it wasn't meant to be cruel) or the latter's Innocently Insensitive comments. As the story continues, the slights and frustrations that K.O. actively suppresses build up from Dude, Where's My Respect? to simply transforming into a Tyke Bomb that needs to be controlled. Shadowy Venomous takes advantage of this for his evil plans towards the end of the series, enticing a team up and encouraging T.K.O. to destroy anything he wants. He sometimes even goads T.K.O. into attacking his friends, as demonstrated when he reminds him that Dendy used him for her experiments when she tries to calm him down, even when she had already apologized for her actions. When K.O. finally discovers how to stop T.K.O. for good, this becomes reconstructed as he accepts T.K.O. not as a representation of his anger and rage, but as himself Warts and All.
• Anvilicious:
  • "No More Pow Cards" had a not-very-subtle racism metaphor, but that's not necessarily a bad thing in this episode's case.
  • The anti-gun metaphor of "Let's Not Be Skeletons" is delivered with all the subtlety of a 200 MPH car crash; it is hardly unbiased or nuanced in its representation of the opposing side, to say nothing of how awkwardly it makes its own argument in both an in-universe and meta level.
  • Downplayed with "Project Ray Way," which has a clear message about consumerism and big brands vs. small independent businesses, but puts it mostly second to the humor, Ship Tease between Rad and Raymond, and the parody of fashion culture.
  • "The Power is Yours" is a Crossover with Captain Planet and the Planeteers, so it's pretty much obligated to include a very prominent and blunt moral about protecting the environment.
• Awesome Music: The extended theme song, which has a great instrumental, stunning visuals, and all-new lyrics.
• Base-Breaking Character: Enid is easily the most divisive character of the main cast, with some liking her for her cool personality and powers while others dislike her aloof nature and the fact she comes off as an uncaring Jerkass. Her tendency to mistreat customers does not help matters, though her fans point out that said customers are usually jerks themselves.
• Big-Lipped Alligator Moment:
  • Carla is seen with a fake mustache during a TV commercial in the episode "Dendy's Power", and again when she meets K.O. and Dendy. It's never explain why she wore it in the first place.
  • In "Let's Take a Moment", the episode starts off like it's being watched by a Studio Audience, which includes a Laugh Track and the audience cheering when Carol enters the scene, and then those SFX ends when Gar enters the scene. While Carol acknowledges the sound of the audience cheering, it's not explained why it was happening in the beginning and no one talks about it afterward.
• Bizarro Episode:
  • "We've Got Fleas" is a spectacle of weirdness. To wit: The Bodega employees become animal people to fight a new robot, they get fleas and try to find a way to change back, learn they can't change back, then attend what is essentially a Reverse Furry Convention, and end the episode wearing costumes of their human selves.
  • "Let's Watch the Pilot" involve the main three, depicted as Animated Actors, riffing on 'Lakewood Plaza Turbo'. Weird enough, but then it escalates into drama with them acting like total divas.
  • "Your World is an Illusion" is about a girl named Holo-Jane opening up K.O.'s eyes to the fact that he's in a cartoon, such as noticing things like the Hit Flash, a Conspicuously Light Patch, and his Four-Fingered Hands. It leads to K.O. having an existential crisis, but Holo-Jane brings him back down when she realizes that even though his world isn't real, the experiences everyone has in the world are.
• Broken Base: Like Steven Universe before it, the show's fandom was splintered over criticism of the inconsistent art style, with some deriding it as cheap and lazy while others were defensive of it due to the fact that the show is animated traditionally and appreciate the effort put into it or enjoy the inconsistent style. The arguments only intensified once show staff revealed that their stance on the matter was that nothing is Off-Model "as long as you can recognize the character." There's also a third group of people that just simply don't care as long as the show itself is good.
• Captain Obvious Reveal:
  • Most fans had already figured out that Venomous and Shadowy Figure were the same person, or at least very heavily connected. While Word of God states this was intentional, the actual reveal is treated as a major and unexpected event.
  • Lots of fans had already guessed that Laserblast is K.O's father, since Laserblast and Carol were dating before Laserblast's disappearance and Carol finding out she was pregnant with K.O. shortly after he disappeared.
• Catharsis Factor: While Boxman getting fired into the sun and Darrell taking his place at first happened because of a bizarre and misguided attempt of the latter to gain Boxman's approval, Season 2 shows that Darrell not only stopped caring about Boxman and his approval, he also managed to run Boxmore better than his father to the point where Cosma has a positive opinion on him and sends his father into a box to "attack" the plaza. After a whole season of Boxman being a horrible father it is quite nice to watch Darrell, who was usually the target of Boxman's anger-induced executions, giving the latter what he deserves; it also helps that Darrell treats the rest of his siblings with much more respect than Boxman ever did, to the point of giving them the chance to watch TV shows other than Boxman's propaganda.
• Crossover Ship:
  • Pairing Carol with Greg Universe has been making the rounds on Tumblr, due to them both being good single parents to their respective shows' main characters (K.O. and Steven) and having their spouses not being present due to special circumstances (Rose giving up her physical form to give birth to Steven while K.O's father apparently died (not really, but it's complicated) before he was born).
  • Some fans also enjoy pairing Carla with Isabelle from the Animal Crossing series, due to both being dog secretaries/assistants.
• Ensemble Dark Horse: A lot of minor characters in the series have garnered respect from the fans.
  • Red Action was quickly embraced by fans, thanks to her rather Animesque design, cool factor, and interactions with Enid. Red's following substantially increased after "Back in Red Action" aired, revealing her backstory as a Sentai-inspired runaway from the future and romantic relationship with Enid.
  • Thanks to Drupe's thick hips and thighs, there's been a lot of fan art of this strawberry girl.
  • Succulentus only appears for a few minutes, but fans were drawn in by his numerous nu-metal references. Helps that he's voiced by Korn lead singer Johnathan Davis, who's clearly having a ton of fun with the role.
  • When Cosma made her debut, people immediately fell in love with her thanks to her design and her Pragmatic Villainy attitude, shown when she points out the problem of Boxman constantly attacking the plaza. Not to mention she's voiced by Marina Sirtis, who played Deanna Troi in Star Trek: The Next Generation.
  • When Enid's Parents were introduced, fans immediately fell in love with them, due to being a incredibly sweet, polite, and cool vampire/werewolf couple. The fact that they're both pretty attractive has also won them some points.
  • Miss Pastel and Koala Princess have quickly garnered love for their Animesque designs and Pseudo-Romantic Friendship vibes.
    • Koala Princess in particular, due to her status as a recursive character from the Show Within a Show of the same name from Steven Universe.
• Epileptic Trees:
  • A particular strong theory in the fandom is that Laserblast and Venomous are related, specifically that they are brothers. This is mostly related to similarities in their design. This often goes hand in hand with the theory that Laserblast is Professor Venomous and/or Shadowy Figure. Season 3 revealed that Laserblast and Venomous are indeed one and the same, with Shadowy Figure being a split personality of him.
  • Another strong theory is that Laserblast is K.O.'s father. This was also revealed to be true in season 3.
  • The show's Distant Finale showed us two teenagers who look like they could be kids of Enid and Rad. With Word of God saying that their parentage was deliberately meant to be vague, fans have been speculating over whose children they are, with the two most popular theories being that they're either actually Rad and Enid's kids, or they're Enid and Red Action's, with Rad acting as a surrogate. However, Ian Jones-Quartey later clarified that they're not related to any of the cast.
• Fandom-Enraging Misconception: Calling out the show for giving its female characters "only one body type" is known to annoy a large number of fans, especially since there are other girls in the show that don't have wide hips, like Dendy, Potato, Miss Mummy, Fink, Foxtail, Mikayla, Ginger, Nanini, Blue Power, Shy Ninja, and Green Guts.
• Fan Nickname: Fans have taken to calling K.O. and T.K.O.'s synchronized Super Mode "S.K.O." or "R.K.O." before the canon name was revealed to be "Perfect K.O.", or "P.K.O." for short.
• Friendly Fandoms:
  • The show shares one with Steven Universe, mainly due to this show's creator having previously worked on the aforementioned show (and also being in a relationship with that show's creator).
  • Many fans of this series are also fans of Glitch Techs due to both having heavy video game influence. Ashly Burch did voice work for both series (Enid in OK K.O. and Ridley on Glitch Techs).
• Genius Bonus: "One Last Score" has a candy called The Ponce that turns someone young again, referring to Ponce de Leon, a Spanish explorer of the 16th century believed to have been looking for the fountain of youth.
• Harsher in Hindsight:
  • All the times Professor Venomous abuses K.O. in some way become much harder to look at after The Reveal that he's K.O.'s biological father. It's even harsher when you find out that he was also Laserblast.
  • A ton of stuff related to original P.O.I.N.T. team—their backstory and the events surrounding the "Sandwich Incident", and what happened to its five remaining members after Laserblast's disappearance—becomes this in Season 3. His girlfriend Silver Spark/Carol mourned his loss and was left to raise their child without him; El-Bow/Gar was kicked out of P.O.I.N.T. for it and blamed himself for causing Laser's disappearance for years afterwards, up to the present day; Foxtail became a Well-Intentioned Extremist Anti-Villain who sought to gain more power to make sure nothing like this would ever happen again; Rippy Roo spent years researching particle physics in hopes of finding a way to bring Laser back; and Doctor Greyman was a somewhat broken man after he lost his powers in the accident that kickstarted the Sandwich Incident in the first place. And then you find out that Laserblast was alive all along, but turned to villainy and became Professor Venomous. What's worse, he was the "unknown villain" who owned the lab and created the weapons that de-powered Greyman, all because he felt deeply insecure about the worth of his powers compared to those of his teammates. This inferiority complex is what drove him to abandon his team once he lost his powers too, and never let them know he was alive. So, so many things could have gone differently and turned out better for want of a nail.
  • Crossover Nexus villain, Strike, was basically a personification of show cancellation, namely ones on Cartoon Network, who K.O, along with Ben Tennyson, Raven and Garnet, fight against. A year later after that special premiered, OK K.O. would end up cancelled itself. Guess Strike won in the end after all.
    • It only gets worse, as in August 2022, as a result of Discovery's merger with Warner Bros., numerous shows were suddenly removed from HBO Max, including OK K.O., and various in-progress cartoons in what's effectively cancellation, with some being rendered unable to be viewed legally as a result.
• Hilarious in Hindsight:
  • A fancomic about K.O. getting bitten and turning into a werewolf was posted a few weeks before "We've Got Fleas," which was about K.O., Rad, and Enid turning into were-creatures in order to combat Mikayla, premiered.
  • The episode "We Got Hacked", specifically the idea of a substance that turns people into glitchy mockeries of themselves, would be mirrored in Pibby.
  • In "You're Everyone's Sidekick", when K.O. suggests for Enid to help others, she hisses at him in a manner similar to Marceline the Vampire Queen from Adventure Time. This was simply for the sake of comedy and a bit of a Shout-Out, but it was later revealed that Enid herself is part vampire.
  • Succulentus is portrayed in the show as being frail and and somewhat out of touch with his constant nu-metal references; something that Carol even points out. At the time of the episode's airing, not only was nu-metal regaining traction in the metal community, but Jonathan Davis' band saw a return-to-form following the release of their 12th album.
  • Enid complaining about the impracticality of her old qipao-type costume's "loin flap" becomes this when you remember her current voice actress, Ashly Burch, played Chun-Li in Marvel vs. Capcom: Infinite.
  • In the episode "Wisdom, Strength, and Charisma", Enid manifested a large humanoid spirit with cat ears during the test. Then in August 2018 premiered JoJo's Bizarre Adventure: Diamond is Unbreakable on Toonami on [adult swim].
  • When Boxman was first introduced, some joked that he looked like a fusion of N. Gin and Onion. "Action News" ends with him holding something with a silhouette that looks a lot like Onion. Said silhouette is later revealed to be more of a Bowser Jr.
  • Rad's "Blorp!" Already funny on its own. Even funnier after also hearing it as one of Archer's exclamations.
  • In "OK Dendy, Let's Be K.O.!", Dendy constructs a body suit in order to stand a fighting chance against Ernesto. It wouldn't be the last time that an aquatic-themed being would use one, as this is what Sonic Juice's weapon of predilection is.
  • In "Seasons Change,” Rad's "powerup" consisted of his skin becoming a shade of Orange. Come Dragon Ball Super: Super Hero and Piccolo, the character Rad's design took inspiration from, is shown to have obtained a powerup that literally turns his skin Orange and is called "Piccolo Orange.”
  • In "Let's Meet Sonic", Sonic (who voiced by Roger Craig Smith here) made a remark on how Eggman is the worst during their inflitration to Boxman's base, Jean-Ralphio style. Cut to the second Sonic movie where the hedgehog (who voiced by the same guy who plays Jean-Ralphio in the movie continuity, no less) does the same thing to diss Snow Dogs with the exact same mannerism.
• Idiosyncratic Ship Naming:
  • Brandon/RMS = "Bearbones"
  • Dendy/Fink = "Kapparat"
• I Knew It!: Thanks to their similar designs and the fact that they're both voiced by Steven Ogg, the fandom has long suspected that there's a connection between Professor Venomous and Laserblast. "Big Reveal" revealed that they're one and the same.
  • Many fans had also long guessed that Laserblast was K.O's father, due to the fact that Carol and Laserblast had been in a relationship until his apparent death. In the same episode, Carol casually reveals to K.O. that Laserblast is his father.
  • Shadowy Figure is another character that has been long suspected to have some sort of connection with Professor Venomous, thanks to their similar designs and also both being voiced by Steven Ogg. "Let's Get Shadowy" revealed that Shadowy Figure is Professor Venomous' Turbo form.
• Jerkass Woobie:
  • Professor Venomous can be seen in a more sympathetic light after his backstory was revealed in "Big Reveal". Back when he was still Laserblast, he was a valued member of P.O.I.N.T. with a girlfriend who loved and supported him no matter what, but he was plagued by crippling self-esteem issues in regards to his powers, which he felt were far weaker than those of his peers. He took to experimenting in secret, hoping to enhance them, but his secret lab was soon discovered and marked for destruction by the rest of P.O.I.N.T. As he tried to dispose of the evidence linking the lab to him, an accident caused it to blow up and disappear; he managed to get out of there in time, but he suffered a permanent De-power as a result. To top it off, he heard his girlfriend say something that made it sound like all of her support for him was false, causing him to flee the scene in shame, not willing to face her or his teammates again. Over the years, he tried to regain his powers with no success, but found a new, more lucrative market in the process: the supervillain market.
  • T.K.O. While initially shown as a bloodthirsty ball of rage, in truth he suffers greatly from a lack of purpose and is implied to be ashamed of his rages but unable to properly control them. He calms down throughout season 2 and becomes very introspective while tentatively forming a bond with K.O. (who promised him he would not lock him away again) but when he slips in keeping his rage in check K.O. locks him in his subconscious, intending this punishment to be permanent. Finally, the only person who gives him any affection and recognition, Shadowy Figure, reveals he only ever saw T.K.O. as a stepping stone to his own goals and held no true affection for him. This upsets T.K.O. to the point of killing Shadowy and trying to kill everyone else and destroy the world. Notably, when K.O. finally accepts him as part of himself, T.K.O. immediately calms down and smiles happily upon fusing with K.O., showing he only ever desired acceptance.
• Just Here for Godzilla:
  • Or, rather, just here for the episode "Crossover Nexus", which features cameos and references to almost every character and aspect of Cartoon Network history. Even those who usually dislike the show tuned in for this special.
  • Many people only tuned in for "Let's Meet Sonic" as well, since Sonic is so popular.
  • Some fans only care about the Venomous and Boxman episodes, enjoying the ship but not caring much for the rest of the show.
    • There are also people who only watch the show for Venomous due to finding him attractive or interesting.
• Launcher of a Thousand Ships:
  • Enid has been paired up with Red Action, Rad, Elodie, Shannon, Carol, and Sparko, and that’s not getting into the fanon that K.O. or T.K.O. has a Precocious Crush on her.
  • Rad has been shipped with Enid, Shannon, Raymond, Drupe, and his van — and similarly to Enid, it’s general consensus that Dendy has a one-sided crush on him.
• Memetic Mutation:
  • On Tumblr, some people have started joking that OK K.O.! is trying to "outgay" Steven Universe (a show known for its many LGBT characters and same-gender romantic relationships), citing the use of Joff and Nick, Enid and her strange interest in Carol, Red, and past relationships with Elodie and Rad, R.M.S. and Brandon, and Rad and Raymond.
  • After the episode "Big Reveal" aired, fans immediately decided that Carol would threaten Venomous into paying the 6-11 years of child support she never got.
• Moe:
  • K.O. himself, especially when he was little and desperately trying to catch that fly in that flashback in the "T.K.O." special. He was even called cute in that episode!
  • Dendy, who's an introverted, nerdy hacker.
• Moral Event Horizon:
  • Played for laughs with Darrell's take-over of Boxmore. True, it is an "act of great evil" that quickly cements as having crossed a line of some sort... based entirely on Insane Troll Logic.
  • A slightly more serious example happens in "The K.O. Trap", when Professor Venomous traps K.O., Enid, and Rad in chambers with goo clones of each other, forcing them to see their friends die multiple times. According to him, these clones had "souls". Even worse after The Reveal of K.O. being his son and him being aware all along of it, showing that he does not have any qualms about seriously injuring, mentally breaking or murdering his own son.
• No Problem with Licensed Games: Lets Play Heroes, the video game for consoles and PC, is seen as being a fairly competently made beat em up, and due to Ian Jones Quartey overseeing the game, has the same feel as an episode of the series.
• Popular with Furries:
  • While there were already a few anthropomorphic characters here and there, when "We've Got Fleas" aired, interest from the Furry Fandom increased.
  • When "Parent's Day" aired and revealed Enid's father to be, in Rad's words, "A Hot Werewolf", the Bara Furry Fans were having a field day with him. While he's not as popular as his wife, he definitely has his dedicated fanbase.
  • Cosma also proved to be very popular with the Scalies (and even non-scalies), thanks to her pretty nice design, wide hips, the outfit she wore when she went to a party, and the reveal that she can actually grow in size to the point that she can literally devour planets and stars. The form also has a smoother voice and she makes a classy pose in front of K.O. and Enid. This form has also garnered some interest from the Macro fans. Being voiced by Marina Sirtis, who played Deanna Troi in Star Trek: The Next Generation also helps.
  • Ever since their debut, Mr. Cardsley and Carla have been decently popular with the fandoms. Carla especially due to the fact that she brings to mind another female dog assistant that's popular. Her positive attitude and energy are added bonuses.
  • Rex th' Bunny, Ian's old OC that made it into the show, immediately got a lot of attention.
  • Resident Mr. Fanservice Professor Venomous caught the attention of the Scalies when he was revealed to have Snake Person traits. His adoptive "humanoid lab rat" daughter: Fink, isn't too far behind on popularity either (for the furries and non-scalies).
  • P.O.I.N.T. Prep Academy students: Koala Princess and Purrcival are rather popular despite being minor characters. Due to being Half-Koala girl and a cat boy respectively.
  • Even for being robots Mikayla also has a few fans for her animalistic attributes, and when a Cat Girl version of Shannon was shown in "Thank You for Watching the Show", it naturally became a hit with certain fans.
• Portmanteau Couple Name:
  • Lord Boxman/Professor Venomous = Voxman
  • Rad/Raymond = Radmond
  • Joe Cuppa/Cupid = Cuppid
  • Rad/Enid = Radnid
  • Red Action/Enid = Rednid
  • Elodie/Enid = Elonid
  • Darrell/Rad = Darrad
  • K.O./Dendy = Kendy
  • Mr. Gar/Carol = Garol
  • Laserblast/Silver Spark = Laserspark
  • Laserblast/Lad Boxman = Laserbox
• Self-Fanservice: Certain fans (especially the ones that enjoy drawing risque fanart) tend to play up the aspects of certain characters. For example, turning Enid's wide hips into thighs and legs that could probably rival Chun-Li's, turning Carol into a muscular Amazonian Beauty MILF, turning Rad into pure Bara fuel and so on and so forth.
• Ships That Pass in the Night:
  • Some fans ship Joe Cuppa with Cupid, despite the two characters never even appearing in the same episode.
  • Even though the two haven't properly met, there are some fans who ship Carol with Professor Venomous, due to the "Laserblast is Professor Venomous" and "Laserblast is K.O.'s dad" theories. Both theories turned out to be true.
  • There are fans who pair Fink and Dendy due to their similar 'nerdy' interests (especially Fink's love of gaming and Dendy's love of computers). An unproduced episode about Fink attending K.O.'s school would have had them meet.
• Shocking Moments: "Big Reveal" certainly took fans by surprise with its eponymous reveal: Professor Venomous is former P.O.I.N.T. hero Laserblast, and is also the father of K.O.
• Toy Ship:
  • It's become common to pair K.O. with Dendy even though they are still children.
  • Though they never met in the show, some fans ship Fink and Dendy because of their similar 'nerdy' interests (particularly Dendy's interest in computers potentially meshing well with Fink's love of videos game).
• Ugly Cute: Lord Boxman is far from conventionally attractive, with his spiky green hair, cybernetic implants, portly figure, and avian talon hand; that said, there are a number of fans who find him rather cute due to his height, his wide and expressive eyes, his Cute Little Fangs, and his over-the-top personality. Boxman's behavior around Professor Venomous (being flustered, eager to please, and openly physically affectionate) have also endeared him to the yaoi fans in the audience.
• Unexpected Character: Seems to be a staple of the series' crossovers; they tend to bring in characters from fairly obscure or older properties that haven't seen use in years.
  • Captain Planet, Kwame, and Dr. Blight guest star in "The Power Is Yours!". Keep in mind that Captain Planet originated in a show from the nineties, with his last appearance in media prior to OK K.O.! being in Cartoon Network: Punch Time Explosion, a video game from 2011.
  • The protagonist of RPG World, Hero, shows up in "A Hero's Fate". It's particularly notable due to the creator, Ian Jones-Quartey, not being completely proud of the comic when he abandoned it.
  • The strangest, but probably most well received case of this yet, is the episode "Monster Party," which features the girls from Scooby-Doo and the Ghoul School. Adding to the surprise is that the characters have not appeared in any media for 30 years, and some of the original voice actresses even returned. It's widely considered to be a pleasant surprise, no doubt due to the girls' Ensemble Dark Horse status in the Scooby-Doo series.
  • For Cartoon Network original shows, "Crossover Nexus" has cameos from a massive amount of them, including characters not seen in years or being known to have been written off, including Ilana and Octus, I.M Weasel, Yumi, Chowder and Schnitzel, Frankie Foster, Juniper Lee, Edd, Grim, Duncan Rosenblatt, Cow and Chicken, Jake P. Spidermonkey, Cap'n K'nuckles, Kiva, Courage, Rex Salazar, Carl Chryniszzswics, Numbuh 5, Major Doctor Ghastly, Larry 3000, Rodney J. Squirrel, Lazlo, Erin, Sheep, Dexter and Monkey, Robot Jones, Festro, and Alfe. One of the greatest surprises is a cameo from Golly Gopher, one of the cartoons from the controversial Out of Jimmy's Head. Also counting is Moxy from The Moxy Show, one of the first Cartoon Network originals.
  • Out of all the crossovers the show has had, who expected them to do one with Sonic the Hedgehog?
• Unnecessary Makeover: Most fans tend to prefer Enid's pilot design over her show design, thinking she looks good with long hair and appreciating the outfit being less revealing and a visual Shout-Out to Chun-Li. Enid herself cringes when she sees herself with long hair and "Let's Watch The Pilot" wastes no time mocking her original outfit by having Enid trip over her loincloth. However, her "Tenid" form brings the long hair and skirt back for one brief hurrah.
• Viewer Gender Confusion:
  • Dendy has a very androgynous appearance and style of dress, and was not referred to by any gendered pronouns in her intro episode. Many fans weren't sure what her gender was until the production notes posted along the episodes confirmed that she's a girl.
  • At first glance, Potato (the little rabbit) could easily be mistaken for a boy.
  • Vormulax's gender was unknown and only guessed at by fans until "Plazalympics", when Enid referred to her as a her.
  • Rippy Roo is female, as per Word of God, but you wouldn't guess by watching the episodes she appears in alone. She has a pouch, like a female kangaroo, but it could be easily seen as a case of Animal Gender-Bender by most viewers.
• Viewer Name Confusion: Many people believe that the protagonist of the show is named OK K.O. His name is K.O., which is short for Kaio; OK K.O. is just the show title.
• Viewer Species Confusion:
  • At first glance, Dendy's appearance made everybody believe that she's a human (or humanoid) until "No More Pow Cards" revealed that she's a kappa. Despite this reveal, she looks nothing like a kappa compared to the other kappas in the show and the only kappa physical feature that we see of her is her webbed feet in "OK Dendy! Let's Be K.O.".
    • That is, until she grows a small pond on her head that she hides under a beret; she also seems to gain greener skin over time, which means that kappas in OK KO's universe develop their species' traits over time, like a human going through puberty.
  • Crinkly Wrinkly looks like a cat at first but he's actually a fox.
  • Some viewers have mistaken Fink for a mouse or rabbit, but she is a rat.
• The Woobie:
  • In a way you have to feel a bit bad for K.O. and Dendy given the fact they both started out friendless due to the fact their peers never really understood them. K.O.'s first companions and real friends were Rad and Enid, and he likewise became Dendy's first friend after she made him her latest research subject. Additionally:
    • K.O., thanks to Shadowy Figure, has a Superpowered Evil Side that desires to break free and take control of his body, and since he's so young and is afraid of having the kind of rage and helplessness that T.K.O. embodies, doesn't really know how to properly deal with it; as he realizes at the end of the series, his attempts to do so were always Not Quite the Right Thing.
    • It's also made pretty clear several times throughout the series that, despite adoring his "mommy", he longs to have a "daddy" in his life, too. This is made even harsher in Season 3 when he learns that Laserblast is his father, and is briefly thrilled about it...but then discovers that Laserblast is now known as Professor Venomous, one of his biggest enemies who's physically and emotionally tormented him numerous times.
    • Until "No More POW Cards", Dendy and others of her species could not be recognized for any heroic acts they might have performed thanks to the rumors spawned by humans against kappas.
  • Pird is an escaped genetic experiment with the appearance of an adult but the mind of a child. This leaves him in a constant state of fear and confusion as he barely knows how to care for himself and needs others to help him.
  • It's also quite easy to feel bad for Enid, despite her snarky and aloof attitude. She's Desperately Looking for a Purpose in Life, spent quite some time as the Black Sheep of her family because her parents didn't support her passion, and her best friend Elodie stabbed her in the back (thus causing Enid to develop quite a bit of cynicism and trust issues.) Her first romantic relationship with Rad ended very poorly, and she's spent some time worrying that her crush, Red Action, won't reciprocate her feelings.

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