"Hey, Puppet Pal Clem! Those are sure sexy jeans!"
Dee Dee: But, Dexter! Your club is for big I-D-K-S-C's!
Dexter: (twisting his decoder ring) I... D... K... S... C? Heeeeey. I'm gonna tell mom!
Dexter: (twisting his decoder ring) I... D... K... S... C? Heeeeey. I'm gonna tell mom!
— "Decode of Honor"
Dexter's Laboratory was one of the very first Cartoon Cartoons, back when executive censorship wasn't as tight-laced, meaning it was able to push the boundaries on what was considered acceptable for kids.
- The entirety of "Topped Off" satirizes drug addiction. In the episode, Dexter and Dee Dee become addicted to coffee and consequently use up the contents of an entire coffee jug. When Mom and Dad find this out, they break down in tears of painful misery, resembling the negative effects of withdrawal from drugs.
- "Decode of Honor": As Dee Dee attempts to complete a task on her list — get a tattoo — she sits down in the tattoo parlor beside a wall of potential tattoo designs, one of which is someone flipping the bird. Later airings and streaming site releases censor this by zooming the shot in to the bottom left far enough to move the design off-camera.
- Dexter accidentally invented glasses that can see through clothes in the episode "A Failed Lab Experiment". To elaborate, a young boy, even if he is a genius, saw the private parts of an obese mailman, an elderly woman, his dad, his mom, and his older sister. Even if we don't see anything from Dexter's perspective, it's still surprising that they got away with it.
- In "Dee Dee and the Man", Dexter has gotten rid of Dee Dee but finds himself desiring company in the lab, so he actually interviews various girls to fill the role of the new "spastic sister". His eventual (instant) choice: a woman at least 10-20 years older than him of supermodel quality. While none of their interactions in the lab suggest anything squick-y, the way Dexter utters nothing but an entranced "When can you start?!" upon viewing the woman is a bit more adult than one would expect.
- Her reaction to Dexter asking to see her dance is even more blatant: "Okay, but it's fifty bucks extra!"
- When Dexter asks the woman to put "more passion" in her pronunciation of What Does This Button Do? (meaning she should be hammier), she misinterprets and repeats the sentence in a very suggestive voice. Dexter even needs to walk off-screen and jump in water before he can continue.
- In one episode Dexter and Mandark face off at each other in their giant robots, ready to destroy each other. They open fire with missiles from their crotches.
- In "Framed", Dexter and a nerdy friend of his, Douglas E. Mordecai III are listening to a scientific program on tape while on the school bus. Dee Dee, who's sitting behind them, unplugs their headphones from the tape player, so that the entire bus can hear the title of the next chapter: "Reproduction". Dee Dee gasps in shock, then makes fun of them for listening to it. One kid on the bus even says "Yeah, well, that's the only way they'll ever learn about it." At the end of the episode, they move on to the next chapter — "Photosynthesis."
- "Hamhocks and Armlocks" was an early episode that got a bit crazy. For example, the waitress at the diner the family stops at is visibly smoking whenever she appears. Not a pipe or anything either, but an actual cigarette. Later, when Dexter is making a robotic arm for his dad, he has a choice of 2 decals to put on it: One that says "Back off!" and one with a metallic naked woman silhouette. He goes with the naked lady.
- In the episode "The Old Switcharooms", Dexter and Dee Dee are forced to switch rooms. Naturally, Dexter is extremely worried about Dee Dee trashing his lab. After an unsuccessful attempt to go through the hallway, he panics and 'suits up' to go through the air vent. This entails tearing apart a stuffed bear to wear its stuffing, thrashing about the room, putting on a lamp shade, and tearing the elastic out of his sister's panties.
- In "Bygone Errors" there's a scene set inside what appears to be an alien strip club.
- In "That Magic Moment," Dexter can be heard mumbling "stupid Irish..." while expressing his skepticism of his Magic Uncle Fergle O'Reilly's magic tricks.
- The gnomes in "Shoo, Shoe Gnomes" are more than a little obsessed with Dee Dee's feet, to the point where she and Dexter use them to distract the gnomes with what is essentially a peep show.
- The commercial for Puppet Pal Jeans seen in the episode "Labels" features some Male Gaze shots of the female models wearing the jeans and has Puppet Pal Clem and Puppet Pal Mitch tell each other that they look hot and sexy in their jeans.
- In "Project Dee Dee", Dexter at one point tries to convince his sister to let him help with her science project by having a robot duplicate of his mother encourage her to do so. The robotic double of Mom reacts in shock to something and the scene pans out to reveal that Dad pinched her butt offscreen.
- "Stuffed Animal House":
- Dexter attempts to pass an animated stuffed rabbit as a hand puppet by shoving his hand up the doll's ass.
- The stuffed beaver ends up used by Dad to scrub himself while showering and runs back to Dexter's lab with a traumatized look on his face, implying that Dad used him to scrub his genitals.
- "Jeepers Creepers, Where is Peepers?" shows baby Dee Dee's first idea, leading to her whole imagination being conceived — literally, via an egg and several sperm.
- In "Height Unseen", Dexter's first method of trying to grow taller is to put himself on the sort of torture rack that is intended for ripping people in half in an attempt to forcibly stretch his body out.
- In "Beard to be Feared", there is a group of criminals who smuggle flour and blatantly treat it as if it were cocaine.Smuggler: I assure you it is 100% pure.
