These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Accidental Innuendo: Much like Stewie Griffin on Family Guy, Wakko speaks with a regional English accent, but uses American slang, including "fanny," which in the US refers to the buttocks. In the UK, however, "fanny" is a crude term for a woman's genitals (which is why those waist packs that tourists wear are called "bum packs" in the UK, because a "fanny pack" — as we call them in America — would sound gross and inappropriate to UK ears).
Another instance of slang which failed to cross over, this time spoken in an American accent: the line "persistent little buggers," spoken in "Critical Condition." In the US, "bugger" referred to someone or something that's bothersome. In the UK, it's used to refer to sodomy (anal sex, though older definitions describe "sodomy" as any sex act that isn't "penis goes into vagina" and, therefore, considered deviant, meaning that oral sex and jacking someone off also counted. In a lot of places, "sodomy" was or is considered a crime).
Any of the songs. Least most of them had some educational value if you remembered the lyrics. So in a way, they were educational television.
And then... Macadamia Nut. The first time hearing this song... well, it's oddly addicting. It's not that it will never leave the listener's head, it is that one may want to listen to it again and again, over and over.
Might have something to do with the fact that it's a parody of the Macarena.
The episode Magic Time had famous magicians Schnitzel and Floyd being abusive to their pet lion and elephant, and later are mauled by said animals in revenge thanks to the Warners. The two magicians are even dropped off in a jungle, where it's quite obvious they get more of the same. As of October 3, 2003, that might not be so funny anymore (but, like The Simpsons example, having either Siegfried and/or Roy get attacked by the animals they use for their magic acts was pretty much going to happen some day. People just didn't expect it to be so soon).
Dot's crush on Mel Gibson has definitely proven to be such of late, given his recent (and sexist) transgressions.
"A Quake, A Quake" is pretty funny, but the end line (which references the then-recent Lebanese Civil War) takes on a new Oh Crap meaning after 2006:
"We want to find some peace and quiet, so we're moving to Beirut"
Genius Bonus: Much like the early Simpsons episodes, the jokes on Animaniacs can only be understood if you knew anything about pop culture. In Animaniacs' case, the jokes aren't as obvious as what The Simpsons puts out, and doesn't always go for what's popular now.
In "Hot, Bothered and Bedeviled", Ron Perlman voiced the Devil. Years later, he'd be Hellboy.
Also, "Hot, Bothered, and Bedeviled" began with a Saddam Hussein-esque dictator of Iraq getting dropped through a trap door into Hell. The Real Life version of this near the very end of 2006 would add a noose, but the principle's the same.
As an airline stewardess, Dot asks passengers if they want "Coffee, Tea, or Monster." These days, the joke goes from being a non sequitur to a pun, as there really is a drink out there called "Monster" (it's a brand of energy drink).
In "One Flew Over The Cuckoo Clock", Slappy, driven crazy after too many talk shows, mentions that it's "Time for Montel and Phil on the Oprah Channel". Several years later, there really IS an Oprah Channel!
And Dr. Phil really does air on the network as well! (Though the Phil she was referring to was Phil Donahue, not Phil MacGraw)
Love It or Hate It: Some of the lesser segments are quite divisive, such as The Goodfeathers, Hip Hippos, Mindy & Buttons, Rita & Runt, Katie Ka-Boom, Chicken Boo, etc. Likewise with some of the one-off sketches featuring none of the usual cast (one notable example being "The Flame", a mostly serious cartoon from the POV of a candle flame who watches Thomas Jefferson write the Declaration of Independence).
"Baton Rouge, Louisiana; Indianapolis, Indiana; and Columbus is the capital of Ohio!..." Jess Harnell can still sing the whole song from memory. Also an awesome Ear Worm.
"Yakko's World" is also legendary — so legendary that Rob Paulsenstill remembers it (even though it's a bit outdated, as a lot of African countries have changed their names due to civil war and unrest and there is no Yugoslavia anymore).
Brain's "Brainstem" (sections of the brain) got a good run as well. Basically any song where anyone lists everything that makes up anything.
"When the whippoorwill / Whippoors in the wind / The wind can whippoor back / Oh nice and chubby baby!"
"The same thing we do every night, Pinky. Try to TAKE OVER THE WORLD!"
Moral Event Horizon: Walter Wolf faking his own death in order to turn everyone against Slappy Squirrel, including her own nephew!
King Salazar the Pushy crossed it when he tried to kill the Warner Bros. (and sis) by blasting them with a cannon. This led everyone on his side to turn against him when they believed that Dot was caught in the blast and killed.
No Problem With Licensed Games: The Genesis game is considered an excellent platformer with puzzle elements, even getting some pretty good reviews in gaming mags when it game out. The Super Nintendo version is a bit more divisive, but overall also considered pretty fun.
Painful Rhyme: The reason why "Yakko's World" wasn't as accurate as it could have been.
The Hip Hippos for their attitudes; luckily the writers took notice and quietly phased them out.
Mindy's mother. She's not merely the one always yelling at Buttons (if he hasn't done something wrong yet, she yells at him to not do something), but whenever Mindy is put in danger, it's because her parents have either left her alone with Buttons and no proper babysitter, or because she wanders off without them noticing. The very first short in fact, she leaves Mindy alone in the backyard in a flimsy safety harness and relies on Buttons to watch her. In short, she is a horrible mother.
Mindy's father is also guilty of the above.
Katie Kaboom for basically having no potential as a character, to the point where her cartoons are almost indistinguishable.
Chicken Boo for similar reasons, though he has some fans due to the surrealness of the one-joke premise.
Seasonal Rot: Some fans consider the Kids' WB! episodes this. They're far from horrible, it's just that the "spark" seems to be missing.
Suspiciously Similar Song: During the Yogi Bear parody in "Back in Style", a song plays that sounds like "Tobaggan Run" by Jack Shaindlin, which was frequently used in early '60s Hanna Barbera cartoons.
When Nickelodeon aired it in reruns, the plastered Nickelodeon logos all over the intro and abridged the theme by speeding up some parts of it.
One would think that a near six-year gap between two volumes would give WB plenty of time to get a decent volume 4 DVD out. The first three volumes had crystal-clear picture quality, but volume 4 has washed-out colors, and the footage is even interlaced. They also didn't bother with any bonus features, they just rushed it for a quick cash grab. Again, considering they had nearly six years to get this right, these kinds of results are inexcusable.
This effect was unintentionally created by some overly literal Russian translations of the show's title. While the official translation was safe, some promotional materials and TV program listings left the "maniacs" part untranslated. In Russian common usage the word "maniac" is used almost exclusively as a synonym for "Serial Killer".
The clown in "Clown and Out". Most victims that find themselves at the receiving end of the Warners' tricks amply deserve it, but he just wanted to cheer Wakko up, not knowing that Wakko had coulrophobia and that Mr. Plotz forced him to perform at the party, not caring that Wakko was hurting him. On the upside, the clown ended up in Mars, where a bunch of blue, mouthless kids actually like him.
Surprisingly, Ralph becomes one in certain episodes, such as "A Hard Day's Warner", in which he is repeatedly trampled by overenthusiastic Animaniacs fans while trying to stop their stampede, and "A Christmas Plotz".