Though not as excessive with the "crap past the radar" moments as the other Cartoon Network-made shows of the late-1990s into the 2000s, Codename: Kids Next Door still has its moments of slinging risque jokes over the heads of the younger crowd.
- "Operation: S.P.A.N.K." (where Count Spankulot joins the Kids Next Door after getting arrested for spanking an innocent child) has a lot of scenes that just seem wrong if you like to let your mind wander into the gutter.
- The Judge's wife (whom Spankulot had accidentally spanked earlier) is seen smiling coyly and waving to him during his second trial, to which Spankulot shudders along with the audience.
- Pretty much the whole episode was messed up, especially Count Spankulot himself. Whether you're for or against spanking children as a means of punishment, there's just something really wrong about a full-grown man dressed up as a vampire running around spanking children because they do bad things (and even some of those bad things are things that kids do that aren't considered wrong at all). Of course, then you see him spanking one of Numbuh 3's rainbow monkey toys later on for seemingly no reason and he was smiling until Numbuh 3 sees him and freaks out.
So wait, she caught him spanking the monkey? - The episode "Operation: D.A.T.E." has Numbuh One and his girlfriend Lizzie hiding in a closet when being chased by a brainwashed group of kids, prompting Lizzie to say: "Oh, Nigey! I definitely want a picture of this!"
- In the same episode, after Numbuh One tells her off, she rants at him with a cup of punch in her hand, obviously not taking his rejection well.
- Lizzie also gets very excited at being over-kissed by a semi-naked, Rainbow-monkeyfied Numbuh One in "Operation F.E.R.A.L." It doesn't help that it's the only way to bring him back to normal. Okay, not really. What really gets him back to normal is when he learns he went through all that trouble...just for a free keychain in a contest from the Rainbow Monkey Corporation.
- "Operation: G.R.A.D.U.A.T.E.S." features all of the good guys save Numbuh Two's little brother being transformed into animals by the series' arch-nemesis, Father. As this happens, the Numbuh 44 twins witness the extremely-abrasive Numbuh 86 get transformed into an Irish Setter—thus a literal bitch. Their only response: "Well, that figures."
- The Age-o-tonic Birthday Suits... Tommy mistakes them for something else.
- In "Operation: P.O.P.", Numbuh Two is being interrogated by the Soda Control Board. His response: "Go suck on a straw."
- "Operation D.O.G.H.O.U.S.E." has a fun one at the end of the episode. After the teacher has her weredog-transforming necklace removed, we cut to the teacher talking in front of her class while holding a book titled, "Divorce Law."Teacher: ...And that, class, is why you should never accept a necklace from your angry ex-husband.
- Numbuh Two (explaining to Cree what he put in a fondue serving, ending with taffy): You know, they say taffy is an amnesiac.note
- "Operation: S.P.I.N.A.C.H.": Numbuh One: "I will not eat it [the spinach]/Not even a scrap!/I will not eat it/it tastes like— (cue Spinach Inquisition dumping him into spinach)
- The Big Badolescent in the Hungarian dub is given the name Csúnya Csitribanc, where "csúnya" stands for "ugly", while the second half is a combination of the words "csitri" and "ribanc", both are insults that translate to "bitch" or "whore" in English. So, in Hungary, she's called "The Ugly Bitchwhore."
- "Operation: S.U.P.P.O.R.T.", full stop. How often does one see brassieres in a children's show, let alone an entire episode dedicated to bras?Numbuh One (while wearing one of Cree's bras): What's the matter, teen-ager? Afraid we'll put your bras to better use?
- The Hungarian dub of this episode is worse. B.R.A. was, due to lip-sync constraints, rendered as CS.Ö.CS., (translated as "T.I.T.S.") It's spoken out several times in the corresponding episode. For the word "bra" itself, they used the slightly vulgar slang term "csöcsfék", literally "tit-brakes."
- Then there's the fact that about half of the KND's enemies try to eat them or feed them to someone else.
- In Operation P.O.I.N.T., the KND try to check through cars. They get really grossed out and run off as if they saw two people having sex in the car, but it turns out to just be some leftover, rotten fast food.
- Numbuh 1 even says "How can they do that in a car?"
- Heck, the entire episode counts as one, especially where that one dude's girlfriend nervously says "I'm not ready for this yet". Before that she says "If we go up to the Point, it will change us forever" and apparently a common saying is "You go up that mountain a boy, but you come back down a man who knows how to roller-skate!"
- Numbuh 1 even says "How can they do that in a car?"
- In Operation P.I.N.K.E.Y.E., the episode's culprit "shoots" herself with her own pinkeye-infected water balloon slingshot once she's been thwarted. It's just a water balloon and she's actually using it as a cover to make her escape, but nevertheless, the scene's framing and language is very obviously meant to be an analogy for a noir detective story's culprit committing suicide by gunshot to avoid being apprehended.
- When Numbuh 4 sees the literally mountainous mess of Billy's closet in Operation C.L.O.S.E.T., he has this to say:Numbuh 4: My closet's nowhere near as mountain-y and messy as this! This kid's a pro at stuffing his junk!
- In "Operation M.I.S.S.I.O.N.", Captain Stickybeard, at one point, yells "Blow it out your porthole!" when Numbuh 4 tries to tell him what to do.
- "Operation N.O.-P.O.W.U.H." features a villain named Mad Dad whose theme is that he's angry with his child's poor grades, a rather blatant reference to Domestic Abuse.
- In the same episode, towards the end when Gramma Stuffum's food forces are being devoured by the army of hamsters, her minions Liver and the pair of Onions hang from her crotch to avoid getting eaten as well. Considering the way they dangle, it can be taken as particularly and misfortunately phallic.
- Cree's "take the party upstairs" line from "Operation M.A.U.R.I.C.E.".
- In Operation F.L.U.S.H's credit scene, the toiletnator says "Oh, flush," in a similar vain to someone dropping an Precision F-Strike.
- In Operation A.R.C.T.I.C., each member of Sector V (sans Numbuh 4) is hit by a "nude torpedo", and we see the four of them (including the girls) naked, though thanks to the show's style, (what with their thin torsos and massive hands) they are able to censor themselves with ease.
- Numbuh 3 seems to be relying on her hair to cover herself, although you actually can see her body (albeit it appears that she has twisted her body into knots somehow) if you look closely. Not that there's anything to see, though.
- Operation F.O.O.D.F.I.T.E. features a couple numbers written by a special musical guest. Who's that musical guest, you ask? GWAR.
- In Operation B.U.T.T., Numbuh One is nude on the beach. While he hides in a picnic basket, the man lying next to it reaches into the basket and touches something that causes Numbuh One's eyes to widen.
- In "Operation: P.O.O.L.," The full acronym for the Destructively Nefarious Kids's S.P.L.A.T.T.L.E. is "Smart-alecky Prisoner Lobotomizing Apparatus Terrifyingly Tortures Loser Enemy." Not only does this reference use Lobotomy as Cold-Blooded Torture, but it also implies that the DNK do this regularly enough to have a gadget dedicated to this.
- Mr. Warburton himself claims he was dumbfounded at what the censors allowed in the Series Finale, which was full of rather explicit Toilet Humor. Biggest example was the name of the roller coaster that Numbuh One fought the DCFDTL on, the "Drop-a-Log". (It ends with the villains dumped in a giant toilet.)
- In fact, the whole amusement park is toilet themed. The implication isn't very pretty, it's even outright stated by Adult!Numbuh 3 that it smelled horrible and was torn down because of it.
- We also get this gem from Toiletnater:
- in Operation: Z.E.R.O.Father: "Sorry about the mess, like i give a doo doo anymore."
- S.P.A.N.K.E.N.S.T.I.N.E. ends with Numbuh 2 bringing Mushi a sundae only to see her sneaking out of her room with help from King Sandy. He then narrates "Kindergartners, they're enough to make you hit the sauce." Granted, he's talking about chocolate sauce, but "sauce" is slang for alcoholic beverages and the beginning of the episode revealed Numbuh 2 had an addiction to chocolate sauce.
- In Stop the g:KND Part 2, When she finds out that Lizzie is VINE, Kuki reacts with a bleeped-out exclamation of "Holy fuck."
- S.C.I.E.N.C.E. has a french operative holding a stick of licorice in her hand. What's wrong with that? The way she's holding it between her fingers resembles the way adults hold cigarettes and cigars. However some adult villians are actually SEEN with cigars like Mr. Boss and Mr. Baby even though the latter’s cigar is a age changing device.
- Speaking of cigarettes, Numbuh 23‘s real name is Virginia Sims, it sounds too much like “Virginia Slims”... a actual brand name of cigarette!
