Acting for Two: Fairly common. Aside from the aforementioned characters voiced by Ian and Parker:
Courtenay Taylor (K.O.'s current VA) also voices Blue Power and Hon Dew.
Ashly Burch (Enid's VA) also voices Gladys (who was voiced by K.O.'s VA in the pilot), Ms. Mummy, Foxy (Ted Viking's talking fox scarf), Rippy Roo, and Cherry.
David Herman (Mr. Gar's VA) also voices Brandon, Jethro, Beardo, the menu announcer in the mobile game, and the Action News 52 announcer.
Chris Niosi voices Nick Army, Pird, Ernesto, and Neil.
Melissa Villaseñor (from Saturday Night Live) voices Punching Judy, Mega Football Baby, Drupe, Potato, Gertie (who had the same VA as Carol in the pilot), and Ginger (who had the same VA as Enid in the pilot).
While he only voices Boxman in the final show, Jim Cummings also voiced Beardo and Viking Ted in the mobile game.
Kari Wahlgren (Shannon's VA) also voices Vormulax and Chill Cat.
Robbie Daymond (Raymond's VA) also voices Rex Th' Bunny and Co-Bruh.
James Urbaniak voices Mr. Logic and Joff the Shaolin Monk.
Michael-Leon Wooley voices Cool Sun, Bell Beefer, Ted Viking, Big Bull Demon, and Galgarion.
Steven Ogg voices Professor Venomous, Laserblast, and Shadowy Figure. They're all ultimately revealed to be the same person.
Clancy Brown voices Mr. Cardsley and Pavel (Dendy's father).
Nichole Bloom voices Carla, Pepelina (Dendy's mother), Nanini, and Bobo.
Dave Fennoy voices Ofrang (Rad's father) and Bernard (Enid's father).
Melique Berger voices Theodosia (Rad's mother) and Wilhamena (Enid's mother).
Adored by the Network: Back when the show premiered, it got the second-most airings of any show on the channel (behind Teen Titans Go!) and had promos aired during every show on the channel. It also was promoted on the channel many months prior to its premiere. It even got to air on Boomerang as promotion for the show and channel, a practice that previously occurred with Teen Titans Go! and The Amazing World of Gumball. The following year, however, this trope was no longer in effect, and the show got the opposite treatment.
Approval of God: Ian JQ frequently expresses fondness for fan art and other fan creations on social media, including going so far as to state that all OCs are canon.
Colbert Bump: Though they weren't obscure to begin with, being from the most well-known of the "Red Shirt Shaggy" movies (which inexplicably gained in popularity a few years prior), the Grimwood Girls saw an increase in fanart after the premiere of the episode "Monster Party".
Ian Jones-Quartey voices Radicles, Darrell, Gregg, and Crinkly Wrinkly. He also voiced A Real Magic Skeleton and Mr. Logic in the mobile game.
Storyboard artist Parker Simmons plays a variety of minor roles, notably including Gerald Nametag, Fishdude, and Gil Ferris. This mainly happens in episodes he himself boarded, but there have been a few exceptions (such as "Legends of Mr. Gar" and "No More Pow Cards").
Fandom Life Cycle: This show just barely reached stage 2 at some point during its run and then stayed there. Fans often blame the series having been Screwed by the Network for its lack of popularity.
K.O. was voiced by Stephanie Nadolny in the pilot, most of the pre-series shorts, and the mobile game, but was replaced by Courtenay Taylor early on in the series due to scheduling conflicts. Due to the difference between the order of voice recording and airing order, K.O.'s voice changed erratically between the two during the shorts and the first thirteen episodes.
Mena Suvari voiced Enid in the original pilot and the mobile game. Come the minisodes and the full series, Enid is now voiced by Ashly Burch.
The standard robot enemies in the mobile game were voiced by the game's developers, while the final show uses different VAs.
Aaron Eves plays Mr. Cardsley in the video game for the series, Let's Play Heroes, rather than his voice actor in "No More Pow Cards", Clancy Brown.
Johnny Wu replaces James Urbaniak as Joff in Season 2.
In "Monster Party", which features the Grimwood Girls from Scooby-Doo and the Ghoul School, Natalie Palamides voices Winnie instead of the late Marilyn Schreffler, and Kristin Li voices Tanis instead of the retired Patty Maloney.
The Other Marty: As mentioned in The Other Darrin above, K.O.'s voice actor was recast early on in the series. Most of the episodes that Stephanie Nadolny, K.O.'s first voice actor, recorded were re-recorded with Courtenay Taylor, K.O.'s second voice actor. The re-dub was mostly unnoticeable, but a couple mistakes slipped through the cracks:
In "Legends of Mr. Gar", all of K.O.'s sound effects and one full line ("Haha, yeah!") were voiced by Stephanie Nadolny, and the rest of K.O.'s lines were voiced by Courtenay Taylor.
In the ending credits of "You Are Rad", Stephanie Nadolny is credited as the voice of K.O., even though K.O. was voiced by Courtenay Taylor in that episode.
"Plazalympics" was written to air almost sixteen episodes earlier than it did, hence why K.O. and Potato seem much less familiar with each other than they were in "We've Got Fleas".
"Final Exams", the episode completing the POINT Prep arc, was released on the Cartoon Network app/on-demand service in September 2018, following on from the rest of the arc. It didn't air on the TV channel until May of 2019, with "Crossover Nexus", Halloween, and Christmas episodes having already made their cable premieres (coming after the previous POINT Prep episodes). As a result, Enid appears to have suddenly returned to the Plaza when she was supposed to be in the middle of attending POINT Prep.
"Soda Genie", "CarolQuest", and "Boxman Crashes" were also released onto the app at the same time as "Final Exams", while "Plaza Alone" would release on the app in December 2018. All these episodes made their cable premieres in May 2019. Outside the aforementioned issue with the POINT Prep storyline, the order for "Soda Genie" & "CarolQuest" is reversed, and "Plaza Alone" comes before "Boxman Crashes".
Steven Ogg, a man normally known for playing villainous roles (including this show's Professor Venomous and Shadowy Figure) or Ax-Crazy psychopaths (like Trevor Philips), voices Laserblast, a hero.
Also, David Herman as Mr. Gar — a no-nonsense, deep-voiced muscular warrior/manager — is much different from the usual wimpy/nerdy characters he plays, like Michael Bolton, Mr. Frond and about a billion different people (typically "twig boy" antagonists, or else the violent moron Jimmy Wichard) from King of the Hill. His voice is so deep it's actually difficult to recognize him.
Asexual voice actress Erica Mendez voices the lesbian Hue Troop Black Strategy.
Enid is bisexual and her voice actress Ashly Burch came out as queer and pansexual in July 1, 2022.
Refitted for Sequel: "Let's Meet Sonic!" was proposed as far back as Season 1 and considered for Season 2, but Sega didn't get back to the crew about it until around the time Season 3 started production.
David Coburn and LeVar Burton return to play their respective roles as Captain Planet and Kwame in "The Power Is Yours!".
"Monster Party" has the monster girls from Scooby-Doo and the Ghoul School make an appearance, with Susan Blu (Sibella), Pat Musick (Elsa), and Russi Taylor (Phantasma) reprising their roles.
In Latin Spanish, Mario Castañeda returns as the Captain (from seasons 2 and 3), as does Luis Alfonso Mendoza as Kwame (from season 2).
In Hungarian, Captain Planet (Aladar Lakloth), Kwame (Karoly Kassai) and Dr. Blight (Agnes Csere) keep their voice actors from the original series.
Saved from Development Hell: The pilot was made in 2012. It went so long (around three years) without further development that the creator called it "the short that you never thought anything would happen with" when the mobile game and shorts were announced in early 2016. It eventually became a full series by Summer 2017, only to end two years later.
Following the episode "Crossover Nexus", the show aired new episodes on Sunday afternoons with no advertisement except on social media and with the day of the premieres in question. There were also little to no reruns, and episodes were often released early on the CN app. Then they sat there for months before actually premiering on television.
When marketing the series' finale, CN never even acknowledged that it was the final episode (much like what happened with The Amazing World of Gumball, though, in the latter's case, it may have something to do with a possible finale movie).
OK K.O.! was originally meant to be one of the flagship shows of WarnerMedia's streaming platform that would eventually emerge as HBO Max. The lawsuit against AT&T's acquisition of Time Warner from the Trump administration led to said platform's delay, and in the meantime, OK K.O.! was sent off to Cartoon Network, where it eventually languished from lack of advertisement (see above).
HBO Max itself would later remove the show from their service in August 2022.
Ian Jones-Quartey confirmed in a Reddit AMA that Enid is bisexual and Red Action is gay.
During a Q&A Twitter Thread, Toby revealed Enid and Red Action's first date was "Back in Red Action", they were dating casually for a while and became a more committed couple somewhere around "Red Action to the Future".
During a Q&A Twitter Thread, Ian reveals Professor Venomous is bisexual and everyone in the Hue Troop is LGBT (but didn't specify further). But in June 2021 Insider.com, the Hue Troop are stated as lesbians.
Ian Jones-Quartey confirmed that Gregg is non-binary and Bobo is agender in his Twitter.
Toby Jones stated that Rad's gender is fluid.
Ian Jones-Quartey confirmed that his character Rad and Raymond are mutually attracted to each other, finding each other "hot and handsome" in his Twitter.
Boy, did this show have a ton! The original pitch was titled "Super Lakewood Plaza Turbo" before being shortened to "Lakewood Plaza Turbo" for the pilot. When the mobile game and the shorts were greenlit, creator Ian Jones-Quartey considered re-naming the show "Guys, Gals, and Pals" (brought over into Steven Universe as the G.U.Y.S. and G.A.L.S. toylines) before choosing "OK K.O.! Lakewood Plaza Turbo", which was shortly changed to the current name "OK K.O.! Let's Be Heroes". Mini Maulers was also a potential title.
There were other scrapped working titles that never got pitched and some got canned for legal reasons. Some of them include: "Lakewood Rumble", "Super Lakewood Action Plaza" (SLAP for short), "Knockout Friends", "Radical Knockouts", "PlayFighters", "Turbo Friends Punch", "Friend Fighters", "Punch Buddies", "Super Chuckle Sandwich", "Action Sandwich", "Knockout Club", "Punch Buffet", "Mighty Mall", "Punchtown Heroes", "Mini Maulers", "Streets of Friendship", "Rumble Pack", "Dynamite Shop", and "Knockout Pals".
"T.K.O." (the episode, not the character) was originally just "Turbo", as shown by the model sheets.
Wrap It Up: The third season was this. Early into the production of said season, Cartoon Network announced that they were cancelling the show. In response, Ian Jones-Quartey and writer Toby Jones would go on to ask the executives to give them the breathing room need to restructure the season in order to wrap up all their plotlines, since they were early enough in the process that they had only just finished outlining the episodes they originally going to do. The higher-ups agreed, and so the previous outlines were scrapped in favor of creating the more serialized final season.
Write What You Know: As per Word of God, K.O.’s interactions with Rad were based on Ian JQ’s relationship with his older brother.
