OK K.O.! Let's Be Heroes Season 3

K.O., Rad and Enid are now full time heroes at the Bodega, with new hires replacing their old positions. Mr. Gar and Carol send the trio out while Dendy acts as their off sight support. While everyone is happy with the new set up, K.O. feels that he is not contributing much and is concerned when a dragon begins attacking Ted Viking and Foxy's house.

When Dynamite Watkins confronts K.O., Rad and Enid on their team name, they realize that they do not have one. They decide to come up with some sort of gimmick, with Drupe's help, so that they can think of a cool name. However they cannot decide on their costumes which is made more infuriating when Raymond arrives to once again mock them.

Carol decides to let K.O. take care of himself for the day while she is out. As a friendly gesture, K.O. visits T.K.O. inside his brain and they decide to switch places for fun. However, T.K.O. ends up being rowdy and breaking all the rules that Carol has set up. As K.O. realizes the error he has made, he is forced to make a harsh decision against T.K.O.

As the public wonders what has become of Chip Damage, Elodie recruits K.O. in reactivating the Chip Damage robot in an attempt to improve on him and bring hope back to everyone. In their haste, they end up damaging Chip Damage's image and it takes an intervention from retired hero, Dr. Greyman, to remind them what makes an actual hero.

K.O. loves his mom Carol, but Fink arrives to turn that all around by making fun of him and calling him a "mama's boy". Feeling miserable, K.O. gets help from his "inner monologue," which is actually Shadowy Figure, to get even with Fink by getting angry. K.O. channels his anger to battle her, but it only seems to make her even more malicious.

K.O., Rad, and Enid break into Boxmore to get back their doors when they find themselves in a box shaped room that does not have any doors or windows. As they wait it out, they begin to realize that something is not right. Rad and Enid are, in fact, replaced with goo clones and K.O. must now get to the bottom of this mysterious situation.

Rippy Roo makes a sudden appearance at the plaza and immediately begins catching up with Carol by revealing what she had been doing all these years after leaving P.O.I.N.T. Meanwhile, K.O. ventures into Rippy Roo's pouch after a creature called a Mecha Maw steals his prized binder of very rare Pow Cards.

Rad goes to Planet X to join his family reunion. Upon arriving he is shocked to discover that the majority of his family are nerds. He later learns that his grandfather, Coach, is a jock and that X-ians have been split into nerds and jocks after humans visited the planet years ago and shared many of their existing culture with them.

Noticing that K.O. and Enid are sad that Rad is still on Planet X, Mr. Gar gives them his old space bike and tells them to take a vacation. The two arrive only to learn that the shape shifting Cosma has devoured the planet whole. As K.O. and Enid desperately attempt to rescue the planet from being digested, Rad and his family do not seem to care.

The Bodega is unexpectedly visited by Sonic the Hedgehog and Miles "Tails" Prower, who aid K.O. in rescuing his friends from Lord Boxman. As Sonic tries to help K.O. with new techniques, Tails feels left out especially when Sonic starts calling him his "little buddy". When K.O. gets roboticized, Sonic must return him to normal.

Carol casually reveals to K.O. that Laserblast is his father. He is excited at the prospect that he has "hero blood" in him and takes on another mission from Mr. Gar to confront Lord Boxman and Professor Venomous. However, Venomous reveals that he is K.O.'s father and soon a distraught Carol arrives to learn the origin of his villainous transformation.

Rad starts feeling uncomfortable when K.O. begins exhibiting negative behavior that he picked up from him, Mega Football Baby and Bellbeefer. He tries to hide his love for kittens as well as him volunteering at the local animal shelter. When Mikayla infiltrates the shelter and begins attacking everyone, Rad has to convince K.O. to drop the macho thing.

Carol drops K.O. off at Boxmore for the weekend so that he can spend time with Professor Venomous. K.O. is disappointed to learn that Venomous is nothing at all like him, so he suggests that they look for Shadowy Figure so that they can "destroy" him. As they look for clues on where he might be, Fink is holding a secret back about her villainous boss.

When the power goes out at school, K.O. and Dendy go out and investigate. K.O. feels bad for Dendy because the other students continuously praise him, but look down on her. They discover that Small Calf Demon is behind the power outage, but when K.O. gets kidnapped by him, Dendy must step into action and use her techno abilities to defeat the villain.

Rad and Red Action once again get caught in a feud. Getting annoyed at how far their bickering has gotten, K.O. and Enid use Red Action's time travel belt to travel to the past to make sure that the two do not bicker with one another. When they cannot find the problem, Rad finally reveals that it involved the events of "You're Everybody's Sidekick".

K.O. once again is spending time with Professor Venomous in an attempt to bond with him. He creates Carl, a gelatinous blob-like creature, but it ends up getting loose, forcing the two to chase it down. As Venomous starts to become distant from the whole ordeal, K.O. begins to suspect that something is up, resulting in T.K.O. taking charge.

Sometime after the previous episode, T.K.O. and Shadowy Venomous have become a terrifying duo laying waste to everything. Dendy attempts to cheer everyone up to no avail. When Lord Boxman is kicked out of Boxmore, he abandons his bots as he feels that he can no longer provide for them, resulting in Dendy recruiting them as the Plaza's new saviors.

The Pow Card company decides to hold a tournament with T.K.O. joining for his and Shadowy Venomous' own nefarious scheme. Rad and Enid join in to rescue their friend and stop the villains once and for all. Shadowy Venomous manages to secure the glorb tree for himself and plans to drain the powers of all the heroes in the world. K.O. fights his way out of T.K.O.'s mind and discovers a hidden memory that could very well save his and everyone else's lives.

In this epilogue, K.O. finds his life moving unexpectedly fast, as he begins missing moments in his life. As many of his friends and family grow up and move on, he begins to suspect that a villain is behind this odd conundrum. However, no matter how many villains he faces, he cannot keep things from changing. He learns to accept that he needs to grow up and move on in life. A final montage plays depicting what became of everyone, ending with K.O. becoming the new owner of the Bodega and signing off with "Thank you for watching the show!"