- "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.
- The following from "Operation: B.E.A.C.H.":
Numbuh Four: Kuki, you're not gonna marry that dork, are you?
Numbuh Three: Of course not! We're just pretending.
King Sandy: Pretending?! The king never pretends!
Numbuh Three: What are you, nuts? I can't get married for real. I'm like 10 years old!
King Sandy: (leans in close) That's okay! I've always liked older women! (purrs)
- 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.
- "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, two Kids Next Door operatives witness the extremely-abrasive Numbuh 86 get transformed into an Irish Setter—thus a literal bitch. Their only response: "Well that figures."
- 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's why you never accept a gift from your creepy ex-husband.
- Numbuh Two: (explaining 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."
- Speaking of the B.R.A. episode, how often does one see bras in a children's show, let alone an entire episode dedicated to bras?
- 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 fast food.
- Numbuh 1 even says "Ugh ... how could they do that in the 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 "Ugh ... how could they do that in the car?"
- The Age-o-tonic Birthday Suits ... where Tommy mistakes it for something else.
- In Operation P.I.N.K.E.Y.E., the episode ends with Nurse Clairborne shooting herself with a water balloon loaded with pinkeye in front of Numbuh 2 to avoid being apprehended by the KND for purposely infecting the students with pinkeye so that she could harvest it for her world famous crumble surprise, although it's implied that she's not actually dead, and given the show's nature, it's not an actual gun, but a slingshot powered water balloon launcher.
- Not merely implied. She did come back in a later episode and made a Call Back to pinkeye.
- 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.
- One Starter Villain for "Operation N.O.-P.O.W.U.H." has a rather blatant reference to Domestic Abuse.
- Cree's "take the party upstairs" line from "Operation M.A.U.R.I.C.E.".
- In Operation A.R.T.I.C., each member of Sector V (sans Numbuh 4) is hit by a "nude torpedo", and we see the 4 of them (including the females) naked, though thanks to 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 if you look closely. Not that there's anything to see, though.
- 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 using Lobotomy as Cold-Blooded Torture, but it also implies that the DNK do this regularly enough to have a gadget dedicated to this.
- In Operation S.P.A.N.K.E.N.S.T.E.I.N. The episode ends with Count Spankulot and Numbuh 2's grandma talking about the old times over dinner, up to the credits reel. At the end, Grandma asks "So, Spankulot, are you married?"
- 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, It's even outright stated by Adult!Numbah 3 that it even smelled horrible and it was torn down because of it.
- We also get this gem from Toiletnater:
Radar / Codename: Kids Next Door
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 does have its moments of slinging risque jokes over the heads of the younger crowd.