In the Aaahh!!! Real Monsters episode "Hooked on Phobics", Ickis is humiliated in front of the class after getting injured on a scare assignment. He packs a suitcase full of comics and prepares to run away. If you watch closely you'll set that in addition to the comics he grabs, Ickis also packs "Shnookie", a sponge he used as a security blanket in "It's Only a Movie".
A subtle Continuity Nod can also be seen in the background of Ickis, Oblina, and Krumm's dorm room. A picture from an old vacation hangs on their wall, showing the monster trio in Egypt. Ickis wears glasses in the picture, just like he did in the pilot episode, "Monsters Get Real".
In the Adventure Time episode "The Real You", Finn puts on mind-enhancing magical glasses, and an Astronomic Zoom happens to establish his sudden understanding of the universe. When it zooms in on the planet, you may not think that there's anything odd about it. But if you pause just as it flashes by, you can see that the planet has an enormous crater in it. Like, a moon-sized crater.
A snail makes a brief appearance in the background roughly Once per Episode (complete list of appearances here). As of the season 2 finale, it has been possessed by The Lich.
In "What Is Life?", the pictures in the book Finn reads while brain-storming ways to prank Jake have various silly captions◊.
In "Mystery Train", while Finn is flipping through the pages of the dictionary, you can see a few entries for other words, including "mathematical", "Ice King", and "pancake" (one entry for which reads "Natasha's pet cat").
In "Hug Wolf", you can briefly see the book in which Jake looks up Hug Wolves has the title "Bestiarium Vocabulum", with the subtitle "(Beast Compendium)", and another subtitle that reads "((Animal Book))", including the extra parentheses.
In "Gotcha!", when Lumpy Space Princess is working on her book near the end of the episode, you can catch a glimpse of one page.
Pause at the right time in "Reign of Gunthers", and you'll see that the Ice King's web search history has some amusing entries, like "wants to rub mayonnaise on a penguin", "wiping my bum isn't working right", and "wrong way to eat a banana".
There's a split-second close-up of a newspaper article featuring Simon Petrikov, the Ice King's pre-Mushroom War self, describing how he found a ancient book. Said book is actually The Heroes' Enchiridion.
In "The Lich", during Finn's dream there is a blink-and-you-miss-it frame of the Lich laughing in Billy's place, as if Billy IS the Lich. If you catch it, it foreshadows a pretty big twist in the plot later in the episode.
In "The Duke", a squirrel is reading a holographic newspaper where there's an advice column by Jake. Next to it, there's an excerpt from the classic 19th century book Advice to Young Men by William Cobbett.
In the first episode of the Alf animated series, there's a one frame gag that is virtually impossible to see without slowing down the video.
In "Dirty Rotten Merlot Shame", Francine's panties are seen for a couple of quick frames after she is dangled upside down by one foot from a hot air balloon.
In the episode "Choosy Wives Choose Smith" if you pause when Simon the cat gets hit by the car you can see that the passenger is Gwen Ling Francine's foster sister who is getting a cigarette lit in her mouth by the driver, Gwen wouldn't be properly introduced in the show until the season 10 episode "Now and Gwen" six seasons later.
"Garage Sale of the Century", in the scene where the neighborhood gangs up on the bear to get their money back, if you pause it frame by frame you can see Batman, Buster, Babs, and Dizzy from Tiny Toon Adventures, and the Marx Brothers among the crowd members.
In "Plane Pals" during the opening scene when the plane takes off you can see that the pilot is the Gremlin from the Bugs Bunny cartoon "Falling Hare".
"Mail Order Bride" has Santa quickly appearing on the roof of the house during the night.
During the time transition in "E-Dork", one of the passing vehicles is Meatwad on a mini-scooter.
In "Total Re-Carl", after Carl's body is destroyed, Frylock hooks his brain to a computer to translate his thoughts but covers them up after seeing how pissed off Carl is.
Oh man, I swear to fucking God, Fry-man, I'm so fucking pissed right now. Oh, and by the way, I hope you enjoy eating your own shit, because I'm about to rip your motherfucking throat out, and shove it so far up your ass, that you have to fart to fucking breathe, fucker.
In "I Don't Want To Spoil The Party," John is searching for Paul, George and Ringo at a Greenwich Village coffee house. As he paces the floor, a Bud Sagendorf image of Popeye is seen framed on a wall. Outside, one of the establishments is "Gettles A-Go-Go," named for Jack Gettles, the producer of the episode at the Canawest studio in Vancouver.
In the early Betty Boop cartoons some of them would contain a single frame of a nude Betty.
BoJack Horseman has so many that one T-shirt in the background of a season five episode said, "Stop pausing and just watch the show."
In one episode, Winslow gives Cat and Dog tests to see what they like and hate. At the bottom of the list is "laissez-faire economics" (which Cat likes) and "a welfare state" (which Dog likes).
In "Hotel CatDog", one of the vehicles outside CatDog's house reads "Willie Nelson Medicare Tour".
One episode of Clone High features flashes just quick enough that you can tell they're going on throughout the episode. In one, Cleo's clothes vanish leaving her wearing only flower-shaped pasties; in another, the words "Scudworth is your favourite character" appear. In the finale episode, Joan of Arc is found naked in bed and quickly pulls the covers up over herself, but if you pause before she does so her left nipple is replaced with the word "NICE" and the right one with "TRY".
I BURIED PONCE
Danger Mouse on the Orient Express has a scene where the famous train is passing signs of European cities it is going through, the signs passing head on to the left and right in turn. One of the signs is the sign for the Willesden Green tube station.
The Daria fandom is particularly liable to focus on minor background characters, giving them Fanon and making them into OC Stand Ins. This is aided by the episode "Café Disaffecto," where one can briefly see Mr. O'Neill's seating charts and thus get canonical names. For example, "Burnout Girl" is apparently named Jennifer, and thus commonly referred to as "Jennifer Burns" in fanfiction.
In "Two-Face: Part 1", it's easy to spot in normal viewing, but still cool to freeze frame Harvey Dent's gruesome half foreshadowed in a flash of lightning.
Pause "Two-Face: Part 2" at the right time and you'll see that Harvey has since actually gotten an ATM card in the name of his alias.
At the end of "Beware the Gray Ghost", look at the top of the blown up People magazine cover when they pan up to show it clearly, and you'll see "Matt Hagen: Man of a Thousand Faces" across the top above the People logo.
Things to do today 5/12 3:00 Coffee break 3:02 Brush teeth 3.05 Check weather
In "Almost Got 'Im", the bad guys play poker. If you look carefully, you can see the Joker cheat by pulling cards out of his sleeves.
Not so easy to spot, but knowing what they did in the above example, you know to go back and look for it. In the Batman Beyond episode "Out of the Past", Just as Ra's Al Ghul in the body of Talia is about to run through Batman (Terry McGinnis) with a sword, he catches the blade in his hands and delivers the sword into the computer's control panel. This sends a highly visible electrical current but non-lethal electrocution enveloping Talia's body where in a couple of frames, Ra's Al Ghul, whose essence had completely usurped Talia's existence, is seen matching Talia's agony during the electrocution.
Near the end of the Justice League episode "Starcrossed, Part III", there's a single-frame Hit Flash when Hro Talek strikes Hawkgirl. This frame is not pure white, but a very washed-out closeup picture of Hawkgirl screaming.
In "Mxyzpixilated", Jimmy hands Clark a comic strip page featuring the titular Mr. Mxyzptlk. There are other comics on the page, Dini The Meany (parodying Calvin and Hobbes and Dennis the Menace and also referencing one of the show's producers, Paul Dini), Gleen (parodying Peanuts and referencing Glen Murakami), Dan Danger (parodying Dick Tracy and referencing Dan Riba) and Zub Street (parodying Momma). You cannot read these strips without freeze framing. Check out the screengrab!◊ As a bonus: the author of the Dini The Meany strip is called Bill Wemissu in a reference to Bill Watterson (Wemissu = "we miss you"), and the authors of Myxzptlk's strip are... Siegel and Shuster!
A less humorous one that's mentioned in the commentary is in the episode where Lex Luthor makes a deal with Brainiac. If you freeze during the bright flash when Brainiac's ship opens, you can see Krypton. The commentary implies that it was a Throw It In! moment.
In Dexter's Laboratory during the episode "Dexter's Rival", during a scene with Dexter at his school desk, if you pause before the camera zooms in on Dexter there is a Bart Simpson-esque character at the desk to the left.
Disenchantment: In "Dreamland Falls", when Luci shows King Zog projections of events on the crystal ball that happened over the past 15 years, during a rapid fire montage Fry, Bender, and Professor Farnsworth from Futurama can be seen for a spilt second in their time machine from "The Late Phillip J. Fry".
In the Ed, Edd n Eddy episode "A Fistful of Ed", there is a moment in the first half of the episode where Ed and Edd appear to be fighting in the school's cafeterianote It was actually Ed who was doing it, due to being so scared at the time. May Kanker appears for a brief moment in this scene.
Freakazoid! does this a lot in its end credits. One episode (which features an extremely long musical number involving the arch-villain the Lobe) contains a rather lengthy (and humorous) justification for it that is not legible without freeze frame: "One time a space ship full of aliens came down and kidnapped our writing staff. The aliens threatened to blow up the Earth with a solonite bomb unless the writing staff wrote a big, splashy musical number for the Lobe. The writing staff worked for days on the song. The aliens were so pleased with it they agreed not to blow up the Earth. So the next time someone says "I don't know why they did that real long musical number in Freakazoid," you can tell them. You can tell them of the time a rag-tag group of cartoon writers saved the Earth from destruction, and that each new day that dawns over this great, big blue planet of ours is due to these brave individuals."
In the Home Movies episode "Curses", Brandon mentions he thought his censored movie was so boring he threw in brief frames of dogs having sex. If you go frame-by-frame around this moment, you will see one.
Every five episodes or so, there is a single frame flash of a blood-soaked GIR. He has something of a blank stare on his face and is in red-eyed "Duty mode". The image itself can be found here.◊
In "The Girl Who Cried Gnome", while the camera is panning down to Zim's base after the robot gopher is summoned for the first time, one can see that there is an apparently live puppy buried somewhere between the Earth's surface and Zim's underground lair.
In "Halloween Spectacular of Spooky Doom" for a couple of scenes a demonic Johnny of Johnny the Homicidal Maniac can be seen among the monsters.
In the Jem and the Holograms episode "Glitter and Gold", a character holds up a music magazine with a top 10 list. If you pause, you can see that except for the Misfits, the bands/artists listed are all No Celebrities Were Harmed versions of actual musicians, including "Pauper" (Prince) and "Rodent" (Ratt).
In the King of the Hill episode "A Firefighting We Will Go" when Hank arrives at the fire station with a Frito pie and looks at the messy room, if you pause it you will see a drawing of a pig labeled "Bill" presumably done by Dale.
In the 90's Looney Tunes short "CarrotBlanca", when Daffy is carrying Bugs' luggage he trips and drops it and for a few frames Elmer Fudd can be seen falling from it.
In 1943's Porky Pig's Feat, Daffy Duck is challenging the hotel manager to a duel ("You have insult me! We meet on the field of onion!"). There is a frame where a cel of Daffy is photographed painted side up, which is viewable if it is frozen at the right spot.
In "The Dover Boys" when Dan Backslide says "confound those Dover Boys they drive me to drink!" and rapidly drinks down shots of whiskey, at one point if you pause it frame by frame you can see the bartender sneak one of the drinks for himself.
In "The Great Piggy Bank Robbery" at the beginning of Daffy's dream when in silhouette he says "I'm gonna pin it on ya see" his silhouette briefly turns into Dick Tracy's for a couple frames.
Also at the beginning when the mailman puts the mail in the mailbox, one of the letters is addressed to animator Rod Scribner.
In the first episode, when Twilight is talking about Nightmare Moon and the Hourglass passes over the unicorn head statue in the background, it changes to look like Nightmare Moon, going back when it is no longer behind the Hourglass.
In "Griffon the Brush Off", when Rainbow Dash and Gilda race to a cloud, each claims to have been first, but Pinkie Pie claims Rainbow Dash won by just a little bit. To the naked eye it looks like a draw, with both arriving in a flash at the same time, but freezing the image at the right time shows Pinkie is right.
In "Sonic Rainboom", when Twilight Sparkle casts the wing-making spell, an outline of Rarity with her butterfly wings appears for a couple of frames in the explosion of light, several minutes before we get to see the results of the spell properly.
When her friends dismiss the broken table as who wants a hammer for a cutie mark, Apple Bloom looks dreadfully upset.
Just before Sweetie Belle starts singing, Scootaloo and Apple Bloom cover their ears.
In "The Cutie Mark Chronicles", during Fluttershy's flashback, at the end of her song, if you watch the upper-left corner of the screen carefully, you can see Rainbow Dash just as she hits her first Sonic Rainboom. See here.◊
In "Sisterhooves Social", Sweetie Belle runs a race with Applejack. At the very beginning AppleJack gets completely covered in mud and they run the race together, it's only until the end it's revealed that Rarity was really the one who ran the race. If you look back at "Applejack's" eyes you'll see that they're blue just like Rarity's, Applejack's eyes are green.
The dog anatomy pictures in the Vet's room all have the outline of Winona, Applejack's dog.
When Spike recovers his normal size and Rarity says "YOU were the rampaging dragon?" Spike grins and strikes a "let me explain" pose for half a second before plummeting to the ground.
In "Baby Cakes", if you look closely during the opening, the babies in the nursery have the same or similar color schemes as other ponies, though most of them match more than one other pony (two that can be pinned down are the ones matching Rainbowshine and Medley).
In the stands near the royalty box is a pegasus mare with Bulk Biceps' body shape and the atypical beehive hairdo, butterfly glasses, and a string of pearls necklace. She has been dubbed "Mama Biceps".
The necklace Tirek wears in the present is the same one Scorpan is shown wearing during their backstory.
Discord-as-a-pony's cutie mark resembles a cyclone or tornado. Appropriate for the spirit of chaos.
In "Twilight's Kingdom Part 2", the cucumber sandwiches Discord offers Fluttershy are cut into the shape of butterflies, or Fluttershy's cutie mark, which makes it even more insulting when he drops them on the ground in front of her.
"Slice of Life": Believe it or not, this appears for a split-second. Seems like the creators were having a bit of fun.
"Marks for Effort": When Cozy is about to reveal to the Cutie Mark Crusaders she failed, she very briefly displays a smirk when she turns her head.
Derpy Hooves'cameos are sometimes this, like in "May the Best Pet Win", where she peeks out of Fluttershy's chicken coop near the end of the "Finding a Pet" song.
This promo from the Hub riffs on the "There's an App for That" adds from Apple. Every pony app shown has an appropriately punny name and a matching icon (e.g. Wikiponia, Hooftube, etc.), proper use of pony terminology for various app functions, and even the "PNN" news article with tiny text which flashes by at the end is fully coherent and readable. Someone at The Hub obviously knew that that the Periphery Demographic would examine every frame for details like that, going so far as to give a Shout-Out to popular Pony Blog Equestria Daily.
In the Mary Shelley's Frankenhole episode "(John) Thomas Jefferson", a scene in the White House's "Oval Office" features a rug with the moderately hard-to-read legend, "Was It Worth The TiVO Pause?"
In "The Prince and the Pauper", when Goofy is shot out a window by Pete's weasels with a spear by his pants, when it shows his underwear hanging from the spear right before water splashes on it the polka dots on the underwear form the word "wow!"
Twice in Runaway Brain, Zazu the hornbill from The Lion King (1994) appears on screen for a few frames. The first time, he's among the debris being sucked into the trap door, and later he comes out of the monster's mouth as he roars at Mickey.
In the special The New Misadventures of Ichabod Crane, when Velma Van Damme the witch turns into a dragon and Ichabod casts a counter spell on her that gives her a second head, in the frames before she grows the second head, a pair of bare breasts appear on her dragon chest for a couple of frames.
The title card for "Totally Into Your Body" is an anatomy diagram accompanied by Walls of Text. Pausing and zooming in will reveal that the text starts off formally describing the functions of specific organs before segueing into unrelated topics and Buffy Speak.
There's a quick shot of Dr. Hissy's schedule when he tells his secretary to cancel his lunch; the most prominent activities listed on it are pilates, yoga, "me"-time, brunch with Mrs. Hissy, pottery class, and "private snake business".
The Chinchilla's schedule is only visible for a second or so in "The QPC", but it's pretty packed. He's got both a magazine interview and a blind date scheduled, among other things.
The 10th anniversary special "Powerpuff Girls Rule!!!" features an extremely brief shot of Miss Bellum's face.◊ It had never been seen during the series run (1998-2005).
If you look closely at Buttercup's Christmas wish list during "Twas The Fight Before Christmas", you'll see that the pages are headed with "Gimme".
Certain shots of the school in "Paste Makes Waste" shows a crudely-drawn illustration of an angry alcoholic father on the wall.
Mac and Bloo can be seen in the background at one point in "Powerpuff Girls Rule".
Dexter appears at Pokey Oaks in one of the episodes.
In The Problem Solverz episode "Funny Facez", many characters◊ from past and future episodes appear in the audience at the funny face show. There's Lidget, Dork Face, one of the alien Girl Scouts and Dr. Kunichi.
Plenty in the Ready Jet Go! movie Back to Bortron 7. At one point in the movie, Mindy wakes up at midnight and tries to make Jet 2 put the hologram of the house back, and Jet 2 instead projects many other holograms that can only be seen if you pause. The holograms include Sean standing with his hands folded, that same hologram with Sean's mouth closed, a hologram of Sydney, a hologram of Sean in his space-suit, the weather balloon from "My Fair Jet", a hologram of Mitchell cackling, a hologram of Sunspot in a Greek outfit from "Jet's Time Machine", a hologram of Mindy in her pajamas on the flying saucer, and a hologram of the pineapple jack-o-lantern from "Jet's First Halloween".
In "But I Have A Receipt", Mordecai and Rigby are spreading the word about how terrible a RPG The Realm Of Darthon is. One scene they show people all the classes of the game, and Mordecai proceeds to flip through the game book. It looks like a blur after the first couple pages, but if you have a quick pause button finger, you can see classes such as Scorpion Lawyer, Goat-Legged Dude, and Space Colon in the book.
In "Starter Pack", if you are fast, you can read "Interns do it for free" in Thomas' bumper sticker.
Also in "Weekend at Benson's". You can notice the jar of Habanero Peppers that Benson eats from says "Pepper on Pepper action".
In the "solid" episode, the clock reads 9:00, but later 4:20 on the VCR.
In The Ren & Stimpy Show episode "Royal Canadian Kilted Yaksmen" when they give there victory cheer and throw their hats and kilts up in the air along with an intestine, right before it falls out of frame a turd wearing a kilt pops out of it.
Rocky and Bullwinkle: An installment of the "Jet Formula" story arc takes place in the spaceship of Moon men Gidney and Cloyd. A book in a bookcase on the ship is clearly titledSex On Planet X.
In the Roger Rabbit short "Trail Mixup" after Roger gets his head caught in a beehive and starts spitting out the bees, if you pause this scene frame by frame you can see that the bees are caricatures of other Disney characters including Mickey Mouse, The Genie from Aladdin, Evinrude from The Rescuers, and Tinker Bell from Peter Pan.
In the Rugrats episode "Cuffed", when Angelica frantically tears open the package to get the toy handcuffs, you can actually see her casually toss away the key that she and Chuckie spend the rest of the episode trying to locate after they get cuffed together.
In a Sealab 2021 episode, Sparks recognizes a line Marco uses for inspiration. As he cycles through his library of movies, a good majority of them (read: all but one) were tentacle-rape hentai, all with hilarious titles and descriptions, but only shown for a second at most.
In "Light Hope", Adora is shown hologram silhouettes of all the princesses who keep the world balance. They only show up for a second, but there are a lot of details. In addition to numerous silhouettes that look like characters from the previous series, Glimmer and her mother Angella have different colors despite drawing power from the same runestone, Scorpia is shown despite having no connection to her runestone, Entrapta is shown despite having no runestone, and someone who looks a lot like Catra is shown despite her not being a princess at all.
In "Moment of Truth", viewers can briefly see a drawing in Rogelio's locker of an imagined baby he wants to have with Kyle.
In "Huntara", if one looks closely at the other clones in Hordak's flashback, one can see that they have green eyes, in contrast to Hordak's red eyes. "Destiny, Part 2" reveals that this detail was significant. Hordak's red eyes indicate that he has self-awareness and free will, while the other clones' green eyes indicate that they are subservient drones.
The Simpsons: This is done right in the below examples, but it's also invoked many times when many scenes changing the setting show sentences with funny one-liners. However, you need to be really on your toes if you want to read a whole line or any others that show up as the scenes go by semi-quickly.
In the intro, the fast camera pan from a Springfield street to the Simpsons' garage looks like a blur at regular speed, but if you slow it down, you can see that it's actually a legitimate (albeit warped) pan across a HECK of a lot of characters.
The new intro includes a billboard during the camera pan of Springfield. It changes every episode, but is usually impossible to read without freeze-frame.
In "Bart's Comet", when the whole town crowds into Ned's bomb shelter, you can briefly see Waldo the first time everyone is shown crowded in.
In "Bart Star", in the scene where the Hills make a cameo, Bill, Dale, and Boomhauer can be seen in the background.
An in-universe example during the episode "I Am Furious (Yellow)" — when the cartoon "Danger Dog" is shown to the school, the creator freezes the frame showing that the chunks of barf are pictures of the animators' and their friends' heads.
If there's a sign for a public event in the Simpsons there's probably something hilarious and easily over looked, such as the "Semi-annual Halloween Festival" or the candy convention next to the candy shaped poison convention.
The Intro reveals that Maggie Simpson "scans" as $847.63 in the grocery store sequence, which was the monthly cost of raising an infant when the show premiered.
When Bart destroys Former President George Bush's memoirs in "Two Bad Neighbors", a small shred of paper briefly passes in front of the camera on which the words "V.P. Quayle" and "embarrassment" are legible.
The end-credits for the in-universe film, "The Poke of Zorro", in "E-I-E-I-(Annoyed Grunt)" also qualify. Hilarious highlights include Posh Spicenote a.k..a Victoria Beckham as "Wise Nun" with Meryl Streep as "Stupid Nun", Cheech Marin as King Arthur and James Earl Jones as "Voice of Magic Taco". There are also shout-outs to John Byner, Eric Roberts, Pelé, and a personal favourite, Spalding Gray as "Gay Seeming Prince".
In South Park episode "Damien", when Damien makes things fly in the cafeteria, you can see Mr. Hankey flying across the screen.
During a thunderstorm in "Rainforest Shmainforest", Stan cries out "Oh my god! I just saw Tony Danza!" The tour guide doesn't believe him until an undistinguished, dark-haired adult male suddenly appears squatting next to the tour group as a flash of lightning briefly illuminates them.
When the six-graders amass at the Return of the fellowship of the two towers, Scott Tenorman can be seen; even though last season he was practically mentally destroyed in Scott Tenorman Must Die(And even created a Ginger-underground gang as a Vendetta against Cartman in a future episode, after going to treatment), but he now has the luxury of acting like a regular boy douche.
In "Skank Hunt" (S 20 E 2), when Gerald steps into Ike's room with its Minecraft Story Mode poster for a chat, a glimpse over Ike's shoulder shows him playing Minecraft.
In "The Passion Of The Jew" right before Kyle wakes up from his nightmare, a photograph of Alan Alda is briefly shown.
In "Batmantis", when Space Ghost starts producing Unsound Effect balloons with his power bands, Zorak prompts him to "shoot the theory of evolution!" Space Ghost fires a blast that produces three paragraphs of nearly-unreadable text offering a tongue-in-cheek explanation of evolution, which appears onscreen for only a brief second.
In "Joshua", there is an extremely fast montage of clips from previous episodes. Hidden within the montage, there is a title card reading "Haven't you anything better to do than to go through this frame by frame?".
"Ocean Gem": During an aerial shot of Beach City and the dry seabed, what appears to be a truly enormous sword can be seen lying to the right of the Gem Temple.
"Fusion Cuisine" has one that doubles as Foreshadowing. When the fusion Alexandrite breaks apart, Garnet can be briefly seen in silhouette as two small figures, each with one gem, before returning to herself as the separation completes. Garnet herself is a fusion, and the two figures would appear to be her component gems, Ruby and Sapphire.
Watching this cassette illegally? Well, were watching you. Legally. Remove your grubby fingers from the play and record buttons. We hope your mothers raised you better than to be little thieves. All copies, dubs and bootlegs will be confiscated. You will be arrested and subjected to prison swirlies. Wipe that smirk from your face. There are no VCRS in jail.
In the All-Stars episode "Moon Madness", The Slender Man can be seen on the far left monitor behind Chris in his control tent when he signs off the show for the commercial break.
Pahkitew Island contestant Scarlett's audition tape mixes this with Foreshadowing. If you look in the background of her bedroom, you can quickly see a globe hanging from the roof... With several knives sticking into it.
In the first season finale of Beast Wars, if you go frame by frame in the second-to-last shot of the explosion, the one where the wreckage flies past the camera, you'll see that included in that wreckage is Optimus Primal's chestplate and head.
Strongarm's old friend Nightra stops by for a visit in one episode, explaining that she's now a bounty hunter and is being chased by a vengeful criminal named Blastwave. Throughout the episode Blastwave repeatedly ambushes the team trying to capture her. If you freeze-frame at the right moments during those attacks you can spot a detail the characters don't notice: Blastwave has a small Autobot symbol near his waist; he's not the criminal, he's the real bounty hunter and is trying to bring Nightra to justice.
The penultimate episode includes a truly staggering and detailed one during the scene where the High Council blacklists Optimus Prime, Team Bee, and all their allies. The viewer is given a quick gallery of tech specs showing everyone who fell victim to the blacklist. It goes by very fast, but freeze framing shows that it includes cameos from and World Building information on almost seventy characters. This includes not only all the Autobots that helped Team Bee over the course of the show, but also all of Team Prime, the Rescue Bots, and various Autobots who were only mentioned or appeared in supplementary materials.
The season three finale of The Venture Bros. has a single frame nip-slip of Dr. Girlfriend.
In universe, the Rusty Venture Show had single frames hiding clues that lead to the location of the ORB, which Billy decoded after years of research and luck.
In season 2 episode 14 of Wakfu, while the girls are taking a bath, Amalia's chest briefly dodges the foreground cover.
In "Chloe", after the bears' crappy, over-the-top presentation crashes Chloe's laptop, you can briefly see a boot log with all sorts of silly messages, including what appears to be the BiOS complaining that the code is "juvenile" ("seriously: this program is for like 9 year olds"), arguing with the web browser ("It's like you are trying to get me fired browser") and eventually rage quitting to a mock blue screen of death ("WHATEVER YOU DID YOU SHOULD NOT HAVE DONE THAT. PLEASE REPLACE COMPUTER")