When Wendy enters the shack at the announcement of the after-party, she is wearing her name tag. However, while she is leaving with the crowd, her name tag is not seen.
When the agents pull up, there's a bumper sticker on the rear bumper. When they drive away, it's not there.
When Dipper and Mabel are in the attic, and Mabel is claiming that there is nothing left to discover about the journal, there are only watermelon seeds on the neck and sleeves of her sweater; the front of the sweater is completely missing the watermelon seeds.
In the shot of the teens dancing, Tambry is wearing her regular day wear instead of the party outfit shown earlier.
When Lee, Nate, Tambry, and Thompson arrive at the party, Lee is wearing a sleeveless shirt. In the next shot, it has short sleeves. When all four are seen dancing, he is sleeveless again.
When Tambry takes a picture of Thompson with his shirt off, the photo is slightly different than the reality.
During the rap scene, the number of Sheriff Blubs' fingers changes.
Lazy Susan's lipstick is missing in two scenes; one where she is entering the Mystery Shack with a pie, and when the ground is shaking from the zombie invasion.
The mess Grenda makes moves when she, Candy, and Mabel are dancing.
The spell Dipper reads from the journal has some Latin words, but are in the wrong declensions and genders.
Dipper mispronounces the spell he uses to raise the dead. In the journal, the incantation's second line reads "Diablo Dominium," but Dipper reads it as "Diablo Dominus."
Agent Trigger and Agent Powers switch places from when Dipper says the curse to when the zombies attack.
The karaoke machine changes places, and even disappears, many times when the zombies are starting to attack the shack.
Mabel's cowlick color changes multiple times, from brown to pink, when the zombies attack.
During one of the shots after the zombies destroy the golf cart, some colored lights can only be seen for one shot above the horde with Soos, as well as some orange and yellow flags.
When Stan is talking to himself about Dipper in his underground lab, the desk, which presumably showed Stan's tattoo, looks different. The altocumulus cloud-looking symbols are upside down and connected to the main body of the symbol, and there are circles in the middle of the outward pointing arrows.
When Stan sees himself in the reflection of 1's hand, the reflection is not reversed.
In the same scene, 1 is shown with a monocle and ripped back cover, which are unique to 3.
The glass from the window that Soos smashed disappeared from the floor when a zombie breaks through the wall.
The TV was on a static channel before and when Soos sits down he says its on Gossiping House Wives.
Journal 3 claimed that zombies were invincible, except when subjected to a three-part-harmony. However, Dipper, Mabel, and Stan kill many, usually by decapitation, skull-crushing, or severing their spines.
Stan & Mabel's microphones aren't plugged in when they are singing.
Whenever Love Patrol Alpha starts to sing together and shatter the zombies brains, the karaoke machine says "We're taking over the dance floor! (Instrumental.)" But whenever it says instrumental, that's the chorus.
During "Taking Over Midnight," when the three are singing "We're queens of the disco!", Dipper steps up, followed by Mabel and then Stan, but when the camera zooms out, the order changes to Dipper, Stan, and then Mabel.
After singing "Taking Over Midnight" by &NDRA, Stan's fez appears while yelling "Deal with it zombie idiots!" It then disappears again in the next shot.
At the end of "Taking Over Midnight" BY &NDRA, when a zombie goes to attack Dipper, all of their microphones are suddenly gone from their hands and are not on the rooftop.
The sun started rising after they sung "Taking Over Midnight" by &NDRA but the party started at 8:00 PM, so there is no way the party could last about eight hours.
Stan activated the Universe portal in "Gideon Rises" by pushing the lever in front of it to the left. But during a full shot of the portal room at the beginning of this episode, the lever is seen facing the right.
When Agent Powers and Agent Trigger look at their screen after Stan activates the portal, Agent Powers sits left and Trigger sits right. They change while the map appeared.
When Stan is looking at the screen in the cold opening, the glow of the screen on Stan's face is not backwards. Both the screen and the glow on his face are able to be read from left to right.
Gabe's piano disappeared when he was talking to his puppets.
The book that fell on the floor at the library disappeared when Mabel was talking to Gabe.
After Bill tells Dipper he's been keeping an eye on him, Dipper's eyebrows and eyes continuously appear and disappear.
When Gabe visits the Mystery Shack, Mabel's braces disappear when she begins laughing nervously.
When Bill first possesses Dipper, his eyebrows disappear.
When Bill in Dipper's body stopped smacking the drawer onto his arm he had two forks sticking out of it, but when he left they disappeared.
When Mabel answers the dressing room door, Gabe is shown carrying a bouquet of pink flowers, however when he enters they disappear.
During the show, when Dipper (as a ghost) is doing the kiss scene of puppets Mabel and Gabe, there is a heart-shaped background close to the socks, but when the camera changes the background is no longer there.
In the theater, Wendy and Bill are sitting in the same seat at first, with exactly one free seat to their right. A few seconds later, they are sitting in two separate seats and there is still a free seat to their right.
Several times throughout the sequence where Bill possesses Dipper, the password bars disappear.
In the attic after Bill possessed Dipper, he was faded like a clone, but his hat wasn't. When Bill as Dipper was outside, all the colors were normal.
While Bill in Dipper's body was speaking to Soos outside the Mystery Shack, his eyes disappear in one frame
The Journal wasn't on stage after Dipper gets his body back.
Several times in this episode, Bill's top hat and/or cane disappear (however this may be because of Bill's pre-addressed ability to hide them behind his body, though he is never seen to move them).
In the scene where Soos and the others are hiding behind the toppled arcade cabinet, the character peeking over the fortress wall on the side of the cabinet changes from a peach color to red in one short scene.
In Hoo-Ha Owl's Pizzamatronic Jamboree, the graphics for Star Battle appear on the unit for First-Person Puncher.
When Dipper tricks the bear animatronic into hitting the win button, Mabel's shoes weren't in the shoe holder. Later, when they were caught, Mabel's shoes are back on her feet.
Mabel buys a sticky hand from a vending machine. The containers are all clear with colored lids, but she's shown opening a plastic Easter egg.
The unnamed man in red appears in the mall once in one area and then another place in a fraction of a second.
While Stan is attempting to get the traveler to come into the Mystery Shack, his mouth overlaps his nose for a frame.
When the Pines first approach the Hand Witch's table, the stall in the background says "Lots O Pots." Later is changes to "Pots Aplenty."
When Stan mocks Dipper's concern about a curse, the stalls in the background change. Instead of Lazy Susan and Old Man McGucket's stalls, Pots Aplenty and Cheep Cheep Tires appear. Additionally, they are transposed (Pots Aplenty was on the right of Cheep Cheep Tires next to the witch's stand).
When Grunkle Stan first grabbed Waddles when he started to tell "Abaconings," the Summerween basket is standing upright. After he put Waddles down on the floor, the Summerween basket is knocked over, and the candy inside it is spilling out.
During the scene in which Mabel and Dipper first see that Waddles is now a genius, the machine that he rolls in on is layered incorrectly with a nearby pile of books.
When Waddles shows Dipper and Mabel the What-the-heck-ahedron, the stack of books was on the opposite side of Waddles, the stuff that fell of the books disappeared, and the What-the-heck-ahedron appeared.
Dipper is floating when Mabel enters the shed, and the ladder isn't there.
The cheapskate's box changed locations.
When Grunkle Stan first throws the grappling hook over the gate, it lands on the ground. When the next shot shows Dipper, Mabel, Stan, and Soos walking up to the front door, the grappling hook is still on the ground, when it should be hooked into the top of the gate, which makes it possible for them to climb.
Lazy Susan's apron stain appears on the right (her left) briefly when her hands are being clasped to the chair. Not long afterwords, when her hands are being unclasped, the stain is again incorrectly depicted on the right.
McGucket had nowhere to hide under the table in Greasy's Diner.
Lazy Susan's purse strap turns from purple to yellow.
Even though Carson was with the other gnomes, in the last shot he takes on more of Shmebulock features.
When Blind Ivan says, "It is unseen," his tongue makes the motion of an "L".
The first time the photos of "suspicious townsfolk" are shown, |Alex's photo isn't there.
The large piece of paper in the middle of the "who is the author?" display disappears the second time the board is shown.
When Mabel is talking to Dipper about Mermando, the picture of a "3" on Journal 3 looks more identical to a "5".
The marker Mabel uses to write "Failed" above her summer romances, wasn't in the previous scenes, and is not in any of the following scenes.
During the scene where Dipper tries to deduce who the author is, the photos of suspicious townsfolk vary between having writing on them and not throughout the scene.
When the group confronts McGucket, Dipper shows him the Journal, but when the screen pans in, it shows Wendy's arms holding the Journal. It switches back to Dipper when the screen pans out again.
When Mabel is talking to Wendy about her failed romances, they change positions so that they're near a billboard, but in following and previous scenes, no billboard is visible.
When Dipper views Robbie's memories, the tube isn't in the container.
When Dipper, Mabel, Blendin, and the guards go to the future, Dipper and Mabel are wearing handcuffs, but in the past they weren't.
The mirror reflects Toby as being much closer to it than he actually is. It also does not reflect the railing that is right in front of it.
The photo and signature on Soos' drivers license change drastically between shots.
Before the final challenge of laser tag, the scoreboard shows Blendin with 764 points but after the challenge, his score has changed to 763.
In the final Globnar scene, Mabel and Dipper keep switching places as they talk with the Time Baby about Blendin's fate and their time wish. Dipper is to the left of Mabel in one shot but in the next shot he's to the right of Mabel then back to the left in the next shot.
In several shots, the bandage on Stan's hand is missing.
When Lolph takes out the tablet, there's a crowd behind him. In previous scenes, other people in general weren't visible.
In the future, Lolph doesn't have shoulder pads. In the present, he does.
In Blendin's flashback, when he was carving his mashed potatoes, from a distance the potatoes aren't carved, but up close they look like Dipper and Mabel.
The time machine isn't visible before it was shown broken.
Soos's piano is completely changed between when it was is the hall and his room. Also, he never even brings the present into his room, and neither does Abuelita.
Blendin's spear isn't in the previous or following scenes.
The time baby's mouth is clean a scene after the crowd is cheering for Dipper and Mabel.
When Dipper and Mabel came back to the present, they are a lot dirtier than they were in the future.
The postcard from Soos's dad looks brand new before he makes the time wish.
In the image where Dipper and Mabel are being chased by Blendin on top of a massive clock, Mabel is missing her braces.
The postcard from Soos' dad has no name on it, yet the mailman knows specifically who to give it to.
Right after the cold opening, when the group finds Robbie in the grave, the pine tree on Dipper's hat is missing when the scene is shown from above.
The sponge that Thompson licked wasn't in the previous or following scenes.
Next to the dug grave where Robbie is mourning the break up with Wendy, there is a grave that says 1989-1971, suggesting that the person was born in 1989 but somehow died in 1971.
The folds on Mabel's happiness chart disappears when the giant bird tries to eat Robbie.
In the scene where Stan is sewing a rainbow afro on a stuffed gorilla, the can of Pitt cola is initially miscolored, but is back to its regular color when it gets knocked over.
The bandage on Stan's hand is missing in a couple of shots, but reappears again.
In one shot when Stan is holding his crossbow, the bandage on his hand is colored black.
When Stan grabs his crossbow and aims it at the hot air balloons there are other weapons in his toolbox. But when he talks to Soos, the toolbox is empty.
Robbie's pictures from a little kid to how he is now contradicts with what young Robbie was shown to be like in "Blendin's Game."
The boxes that Wendy and Tambry are sitting on were turned, then strait and then turned again.
In the diner, Robbie's belt appears blue.
When the teenagers are cheering on Dipper for his idea to tape snacks to Thompson, Linda Cardellini says "Well done" but Wendy's mouth doesn't move (nor does Tambry's).
When Tambry sits down in the booth at the diner, she puts her purse on the ground next to her, but in the next frame it is gone. When she is about to leave she picks up her purse, which was on the seat to the left of her.
The mustard on Robbie's jacket sleeve disappeared despite the fact that he didn't lick it all off.
When the Love God first enters the diner, there are a few frames where he has a double chin (as an animation error).
In the scene where Tambry eats the food with the love potion, Tambry's hair is parted to the right instead of the left.
In the scene where Mabel tells Wendy and her friends about Robbie and Tambry, when Mabel first unfolds her happiness chart, Lee's face is not completely drawn for a frame.
When Nate says Tambry's name (after learning about her and Robbie), his mouth is missing for a frame.
After Mabel and Dipper steal the anti-love potion, it still appears in the Love God's belt when he confronts the two, and the potion remains visible in the belt while another anti-love potion is held by Mabel, Dipper, and the Love God.
After Dipper catches the anti-love potion Mabel throws to him, once he gets on stage, it is no longer in his hands.
When Stan's hot air balloon initially rises, the ropes connecting the ballon to the basket are not seen - only the balloon and the motor.
The banner reading "I EAT KIDS" should not be able to stay up above the Stan balloon because no additional balloons are attached to hold it up.
When the Love God gets back the anti-love potion and talks, the anti-love potion looks much bigger than the potions on his belt.
After the group sees that Thompson is being chased by the security guards, they are on a hill overlooking the concert. However, in the next shot after Thompson is being hit with brooms, they are standing in front of stands.
Stan is shown with two hair pieces standing at the back, but after recovering from the balloon collapsing on him he is shown with three hair pieces standing at the back.
When sitting in the recliner watching TV, there is a pizza box next to Dipper, but in the next shot it's gone, replaced by a can of Pitt Cola.
The appearance of the Northwest Manor is different than when it was seen in "The Golf War".
When Dipper first answers the door when Pacifica arrives, he is wearing his socks. When he finally agrees to help her, he's wearing his shoes.
When the butler pulls the lever to open the gate, the visible gear mechanism does not turn.
When Mabel first walks into Northwest Manor there is a glue gun stuck to her dress, but in the next shot of her it's gone. It doesn't return for the rest of the episode.
The description of Marius von Fundshauser in the guest list at one point reads "Marius Marius von Fundshauser".
The party's guest list has pictures of four people on each page, and each text box describes the people on each side of it. Marius' box only describes him, and not the woman on the other side of the box.
Grenda has two ponytails for a few frames before she makes the truce with Candy and Mabel.
When objects are flying around Pacifica and Dipper, Dipper is no longer wearing his backpack.
The ghost lumberjack shows up to the original party with a bow tie in his beard, but when he turns back towards the manor, it is gone.
When the ghost laughs and his beard blazes before he tricks Dipper into releasing him from the silver mirror, his mouth overlaps his nose.
Candy drips cheese onto the pastries, but later, when she is talking to Mabel, there is no trail of cheese near the fountain or on the pastries. Also, the pastries' appearance has changed.
When Grenda approaches Marius von Fundshauser to pretend that something is on his shirt, a yellow stain can actually be spotted on his shirt momentarily.
Only a few people are holding glass of apple cider before Preston Northwest gives a toast, but after Preston's glass breaks, everyone is holding a glass.
Duchess Wibblebip turns to wood while spitting out a drink, which also turns to wood. However, depending on the shot, the wooden drink appears and disappears.
The wooden people change positions several times.
When Dipper is turned into wood, his bow tie isn't tied. Later, when Pacifica looks at him, his bow tie is tied and when he turns back to normal, his bow tie is untied again.
Like with the butler, when Pacifica pulls the lever to open the gates, the gear mechanisms don't move.
The ghost burns the Northwest family portrait, but when he is looking out the window at the people coming through the gate, the portrait is perfectly intact again.
When the wooden people return to their normal selves, the cider fountain in the background is frozen still.
When Candy, Mabel, and Grenda hug Candy's head spins in an almost full circle.
As seen in "The Inconveniencing" the ice box on top of the roof of the Shack has an opening lid. When Dipper takes a popsicle out of it, it is closed.
While Agent Powers is telling Dipper and Mabel about the doomsday device, Dipper is to the left of Mabel. It then cuts to a close up on Agent Powers. When it cuts back to Dipper and Mabel, they've switched places.
When Dipper and Mabel find the security footage, their reflection in the screen isn't reversed.
At first Stan's suit is buttoned up, but then it's unbuttoned, then it's buttoned again, then it's unbuttoned again, then when Stan goes to refresh his soda, it's buttoned again.
When Stan gives the taxi driver $100 his bandage is missing.
When Stan comes into the portal room the door is open, but in the next frame it's closed, then its open again.
When Stan is reading Journal 1, you can see a monocle. Journal 1 doesn't have a monocle, Journal 3 does.
The restauraunt employee somehow handed Soos his meal when he was still at the ordering machine.
In "Not What He Seems," the left sleeve of Stan's coat is ripped by a tree branch. However, in this episode the tear isn't seen.
When Stan moves to punch Ford, his bandage disappears and reappears the next time his hand is visible.
Ford writes in Journal 1 although that wouldn't be possible because it was shown later in the episode that Journal 1 had no pages left in the book.
In Anomalous Phenomena, the book of anomalies Ford reads in college, the pages with the two-headed ducks and cats call the condition "polycephany," when it is supposed to be correctly spelled "polycephaly."
Ford instructs the recently memory-wiped agents, Trigger and Powers, using a few of Mabel's drawings as decoy paperwork. While doing so, the crayon text "What hath science wrought?" on Mabel's self portrait vanishes and reappears.
When Stan was escaping the angry customers in New Jersey, he is driving in the wrong direction and would have crashed his car into the beach instead of driving through town.
When Ford restrains Stan, a black, upside-down version of his glasses appears above his normal glasses.
Near the end of the episode, Ford has changed out of the clothes he wore in the basement, and into his regular ones. However, the clothes still retain the black color pallet, and only take on their normal ones in the next scene.
The clock in Wendy's room never changes despite the scene lasting more than a minute.
In the scene when Stan is intimidating Duck-tective he is seen with a cleft chin like his brother, Ford.
When Dipper explains the rules of Dungeons, Dungeons, and More Dungeons to Mabel, during the close up of Mabel's face the color of her sweater's collar, which is supposed to be pink, changes to purple.
Mabel's letter to her parents says, "just yesterday gravity reversed itself." However, in "Not What He Seems" Stan says that it is Saturday, and in this episode Mabel says they are having a lazy Tuesday.
Many other errors occurred during Mabel's letter writing. After Mabel wrote, "Just yesterday, gravity reversed itself, almost destroying the universe and totally wrecking the whole town!" it cuts to the TV. When it cuts back to Mabel, that portion of the text had disappeared and Mabel was writing, "But the coolest part of the summer was when Gruncle Stan's twin brother came out of this portal thingy" in the place the text was previously. In addition, Mabel said "Now we have two Gruncles for the price of one!" but didn't actually write it down, but when in cut to her picture, it was written next to it. Furthermore, the ink that the pen used was clearly shown to be pink, until it zoomed in on her picture, where the pen started writing in blue ink instead.
Mayor Beffuftlefumpter's name is misspelled as "Mayor Befufflefumpter.
When Soos walks behind Dipper after he explained "Dungeons Dungeons and more Dungeons", Soos was not wearing his "FCLORP" wristband.
While Stan is stapling the turkey head onto the beaver's body, his burn mark is shown on the left side of his back.
Mabel claims to have eaten the Cheese Boodles without her hands. However, cheese powder can clearly be seen on her fingers.
When Stan swats the fairy on his back, she sticks to him and glitter splatters on the back of his suit. However, in the next frame, the back of Stan's suit is completely clean.
When Mabel is talking to Dipper while Dipper is designing his dungeon, Mabel has a hairband in her hair, then, when she starts talking about how Dipper is spending a lot of time with Ford, she isn't wearing a hairband, finally, in the next scene, she is wearing her hairband.
When Stan places his gum on the opposite side than the 38 on the dice, it becomes invisible when he rolls it.
Dipper and Ford throw the "Death Muffins" into the Impossibeast's mouth, causing them to lose the muffins. When they return to normal size, they are still holding the muffins.
When Dipper puts on the helmet on Ford's head, the repeat of the thought "I miss Dimension 52" is misspelled as "I miss Dimention 52."
When Ford puts the Project Mentem helmet on Dipper, the switch on the top is silver. When Dipper puts it on Ford, the switch is black.
A symbol in the cryptogram is misplaced on the ancient wall Ford found, making the word decode to "FOOJISH."
When Wendy, Mabel, Candy and Grenda enter the gates to the unicorns, their positions (relative to each other) changes between some of the frames. In one frame, the order is Grenda, Candy and Mabel (left to right) and in the next frame it is Mabel, Candy, and Grenda (left to right).
In the first shot of the Mystery Shack after it has been pranked, one of the grafittis of "You Stink" is in neon green, but when it is next seen in a close-up, it is a faded brown color.
When Stan and Dipper are in the hot tub, Stan opens a can of Pitt Cola and Dipper's hands are empty. In the next shot (a wider shot) Dipper has a can of Pitt Cola in his hand, too.
When Mabel is eating marshmallows there is another set of teeth overlapping her top row of teeth.
During the girls' game of Truth or Dare or Don't, after Candy confesses to her crush on Dipper, Mabel says "No" and Candy says "Yes." In the shot when they cut to Candy, her hair is missing from below her ear.
The sign on the large raccoon at Mystery Mountain Mummy Museum reads FIRE RETARDANT RACCOON but its recorded message identifies itself as FLAME RETARDANT RACCOON.
One of Dipper's pictures of Wendy is a selfie of them. In the selfie, Dipper is missing the pine tree on his hat.
When Soos is saying that was fun for 78 hours his mouth disappears for one frame.
When Stan says, "the future," with Soos, Dipper, and Mabel, he has a cleft chin like his brother Ford.
Lee and Nate change up the board outside of the school by rearranging the letters in "SAWDUST INHALATION DRILL- 8:00 GO FIGHTING BEAVERS!" to "NO ESCAPE." However there is no "C" or "P" in the former message, so they wouldn't have all the letters needed to write "NO ESCAPE."
When Mabel and Blendin are laying on the ground, their shadows go in different directions.
When Bill leaves Blendin's body, Blendin's body falls and lands on top of the broken pieces of the glass orb that used to hold the rift. The next scene shows Blendin's body laying besides the glass orb's remnants.
After releasing the rift, Blendin removes his goggles to reveal Bill's deception and then collapses. However, the next shot of Bill rising above the bodies shows Blendin still wearing his goggles.
After Gompers eats a part of Stan's hat, Stan drops his hammer and yells at Gompers. Then the weirdness wave comes, it cuts to Gompers growing, and then it cuts back to Stan, except the hammer is no longer present.
When Stan starts yelling and running away from Gompers, his yells do not sync up. His mouth is closed when a yell is heard.
Throughout the episode, the number of Gideon's fingers changes between four and five.
After the enlarged Gompers eats out a part of the prison, Gideon's finger painting is shown, except the pictures of Mabel have changed places and the word "Love" is no longer present.
After Dipper and Wendy find Soos, Dipper picks up his hat off the ground. However, the hat was in the car and was never shown to have fallen out.
When Dippy Fresh high fives Soos, he is wearing a skateboarding helmet, but in the previous and succeeding shots, he is not wearing a helmet. Oddly, he isn't even wearing the helmet when he is actually skateboarding.
When the younger Dipper shaves part of his head in the flashback, his birthmark is not visible.
In one of the flashbacks, when Mabel gets gum stuck in her hair, it's on her left side, but when Dipper gets her to shave it off, it's on her right.
In Bill's "throne of frozen human agony", Manly Dan is in a different pose than when he was frozen.