"Skeleton Frolics", a sequel-of-sorts to Disney's classic "Skeleton Dance" (and animated as well by Ub Iwerks), has an entire skeleton orchestra assembled. Immediately in front of the conductor is the piccolo player, who in the midst of the piece plays a particularly off-color note while flipping the double deuce. After two or three times, the conductor realizes this is happening and knocks the player on the head, who insists that it's in the music.
"Hercules" In the episode "Hercules and the Big Lie," when Icarus is searching for the flower that can cure Catastrophia, he utters the phrase "pluck and run."
In "Hercules and the Underworld Takeover," towards the end of a characteristic argument between Athena and Ares, Athena says, "Oh, go polish your spear." Younger viewers probably wouldn't thing anything of it, as it makes logical sense, with Ares being a god of war; however, the fact that Athena means it as an insult indicates a double entendre.
Blazing Dragons. A particular example is the allusions to the Arthur/Guinevere/Lancelot triangle of the King Arthur mythos in the case of Queen Griddle's obvious infatuation towards Loungelot. And then there's Sir Blaze.....
On the topic of Sir Blaze, the theme song/title sequence includes the knights extolling their virtues: "We're straight and true and good and kind..." Sir Blaze winks at the camera when he says the word, "Straight."
The animated adaptation of The Mask was a wacky 1990s cartoon, and therefore, was chock full of Parental Bonus and the occasional risque jokes — but...one episode stands out as the reason why American censorship (at least back in the 1990s) is considered a joke by most: season two's "Flight as a Feather," which, along with the standard Double Entendres (The Mask telling the audience that African violets weren't the only things drooping on Mrs. Peenman), your typical gross-out humor (The Mask showing an irate pizzeria customer his green, pulsating guts, and the customer nearly puking), and Parental Bonus references (the mayor implying that he blew the city budget on a party for beauty contest winners), included two scenes that kids' cartoon writers (not even most Cartoon Network writers) wouldn't dream of putting in:
The scene of Cookie BaBoom (the Mayor's suicidal ex-girlfriend who works as an exotic dancer note Smedley almost calls her a "stripper," but corrects himself. Whether or not this was a censorship measure is up for debate) rushing the stage in a trenchcoat and flashing everybody...her bikini made of explosives and holds the Mayor hostage because he broke up with her, followed by The Mask using the explosives on Cookie's body to make a drink known as The Bikini Cocktail. As if that weren't enough, just as Kellaway and Doyle go to arrest The Mask for harassing Mrs. Peenman and a customer at a pizzeria, The Mask uses Cookie's naked body to distract the cops — and it works, even on the hard-assed Kellaway, who can only stammer out "Lady, y-you're under arrest," before sliding to the floor.
What really puts that entire part over the top is the implication that this aired live and that old woman in Bavariaville saw everything (yet only freaked out over The Mask harassing the Mayor).
The performance artist at the pillow feather factory sounds like a mild, but fairly obvious gay stereotype (he has a lisp and comes off as very effeminate). To make matters worse, he's named after a brand of oil (Crisco), which can be (and often is) used as a lubricant for anal sex.
Underdog's arch-enemy was named Simon Bar Sinister. In heraldry, the "bar sinister" is popularly considered to be the sign of an illegitimate offspring (better known as "bastard children").
In an episode of the original G.I. Joe cartoon series, Lady Jaye disguises herself as the Baroness to infiltrate Cobra's headquarters. She then gets into a little exchange with Destro in the following conversation.
Destro: See me in my quarters when you are done, Baroness. I have some interesting hand-to-hand combat techniques to show you. Lady Jaye:(speaking with Baroness' accent) Oh, I could get a real kick out of that. Destro: That playful little minx.
Captain Planet's Very Special Episode about a kid having HIV (!). Or the other very special episode where Linka's cousin gets high on drugs, smashes a closed window, and inadvertently slits his wrist thanks to an aversion of Soft Glass.
In X-Men, the episode "Time Fugitives" features Rogue calling a Friends of Humanity goon a "peckerwood," which not only sounds perverted, but is also a racial slur for a white person (particularly one who is considered "trailer trash" — uneducated, poor, violent, and obsessed with all that is cheap and tacky).
For some old school crap under the radar, don't forget Scooby-Doo. Famous are Shaggy and Scooby's not so subtle hippie tendencies, including constant "munchies" for Scooby Snacks and smoke occasionally coming out of the mystery machine.
Is there anyone left on the Internet who doesn't know that "Scooby Snacks" were code for "hash (or weed) brownies?"
Word Of God states that Scooby Snacks are just dog biscuits. That doesn't change the fact that Shaggy likes them as much as Scooby does. If anything, it only adds to his "stoner" persona since getting the "munchies" would make him want to eat anything that could be considered "edible," whether or not it's food for people.
The first episode of Count Duckula was titled "No Sax Please, We're Egyptian" has the characters singing the "Drunken Sailor" sea shanty. They stop before getting to any of the off-color verses, but suffice it to say, this is not a children's song.
The episode title itself refers to a play in London called "No Sex Please, We're British."
"Duck Dodgers in the 24 1/2 Century" features an episode called "K-9 Kaddy" co-starring the Goofy Gophers. They tickle-torture K-9 then begin tickling each other and run offscreen. They return sighing and exclaiming, "Oh! I couldn't tell you the last time I had so much fun with a feather!"
When the girls initially transform in W.I.T.C.H., the girls grow wings, among other things:
Hay Lin: [looking at her wings] What have we got behind us?
Cornelia: [looking at her chest] What have we got in front of us?
Being based on a Troma film, Toxic Crusaders, a kids version of The Toxic Avenger, had this in spades. One notable example in the episode "Toxie Ties The Knot" had a female alien bug character being kidnapped by the Mayor of Tromaville. Thinking that someone is throwing her a bachelorette party, when the Mayor shows up in a bug costume the female alien asks "Are you the stripper?". This is followed up by Toxie finding the alien bug straddling the mayor, at which point the alien does all but claim rape.