List of goofs

The following is a list of goofs, errors, and mistakes in the series Gravity Falls.

Unaired pilot

 * In the deleted scene where Stan, Mabel, and Dipper are falling into a pit, Mabel's headband mysteriously disappears.
 * In the deleted scene, Dipper's foot is above a background rock.

Tourist Trapped

 * When Mabel punches Dipper, she punches him in the cheek, but his eyes are black.
 * While Dipper was reading from 3, he spoke the word "studying" even though the book states "researching."
 * The book 3 that Dipper discovers has a hand symbol on the book cover that alternates between five and six fingers in several shots.
 * After Dipper and Mabel crash the Mystery Cart, its position moves several times throughout the scene.
 * When Mabel showed Dipper the leaf blower mark, one can see it's there, but when she finishes the story about how she got it, it was gone.
 * When Dipper and Mabel are being chased, a rear shot of the back of the Mystery Cart shows that Dipper's hat is missing despite it being present in the preceding and following shots.
 * The leaf blower sucked Mabel's lips, but the "smooch mark" was on her cheek.
 * Norman has a cut on his face from which "jam" is spilling. Later shots do not include this cut.
 * When you see the triangle stained window from the inside it is centered with a double ring, but from the outside it has a single ring.
 * Up close Mabel's sweater says MEOW WOW, but zoomed out it is wordless.
 * When Mabel is responding to Jeff's proposal, Jeff's beard is red instead of brown.
 * When Wendy pulls up in the Mystery Cart there are four flaps across the top. But when Dipper goes to save Mabel, there are only three.
 * When Mabel is on the floor, her headband disappears.
 * The gnome colossus appears to be all red with a white beard, but the entire colossus should be more varied due to the individual gnome's coloring.
 * In one of the clips that Dipper recorded, when he watches that Norman's hand falls off, the hand doesn't have a brown stick attach it, when Mabel sees that Norman is a bunch of gnomes the hand has one stick attached.
 * Dipper throws a shovel at the gnomes and is shown that it was left at the gnome hideout but later reappears when Dipper grabs it to throw at the giant gnome monster.
 * When Mabel introduces Norman to the family, she says "Ooh, little muscle there" but when Norman reveals that he's a bunch of gnomes, the arms are only sticks.
 * When Dipper throws the shovel at the gnomes, Dipper and Mabel are a few feet apart, but in the next camera angle they're holding each other.
 * When Dipper is looking through the window when Norman is about to give Mabel daises, he screams. When he screams the window is a lot bigger, then returns to normal size.
 * Mabel's cheek mark is much bigger.
 * Dipper says that Norman never blinks but Jeff does blink.
 * On the part it shows the map of Oregon, Corvallis is spelled Corvalis.
 * If Norman's arms are sticks, then he can't bend his arms like he does in many scenes.

The Legend of the Gobblewonker

 * Grunkle Stan's license plate reads "STNLYMBL" which is 8 characters long, but in the state of Oregon, the max number of characters allowed on a license plate is 6.
 * When Soos lost his shirt, it reappeared during one of the fishing pictures and disappeared again after the pictures.
 * When Old Man McGucket says "Aw, banjo polish!" when he was leaving the screen, his mouth didn't move.
 * Soos still had part of his shirt but when he fell out of the boat his shirt was completely gone. Also, he lost his life jacket, but it reappeared.
 * When Soos grabs Dipper by the top of the life-jacket when they are running away from the Gobblewonker, one shot shows Dipper wearing the life jacket, and it is raised up so you can see his stomach. However, when the shot pans out, Dipper's t-shirt that he is wearing under his life jacket covers up his stomach.
 * When Dipper's hat was shown in the picture, all of the letters were the same color, although the time his hat was first shown, it was different shades of blue and the first P was green.
 * Dipper's fishing hat lost the last two letters during the pictures, but later all the letters are back.
 * During Mabel's daydream with the hamster ball, both men had blue sunglasses, but then the glasses turn pink after Mabel talks to them.
 * In the pictures of Stan, Dipper, Mabel, and Soos the letters on Dipper's hat are all blue and the letters on Mabel's hat are all pink.
 * In the first picture Dipper took, Mabel's hat's name colors are the same, plus, before Dipper took the picture you can see Soos' arm, but in the picture you don't.
 * When Soos is throwing the cameras at the Gobblewonker, some cameras randomly appear in his hand.
 * When Dipper meets up with Stan he had his hat on, but when Mabel and Dipper put on his fishing hats, Dipper's hat disappears.
 * When Soos was throwing cameras at the Gobblewonker, he had about 9 or 10. But they only had 8 left.
 * In the same scene, the cameras in Soos' arms reappear after being thrown.
 * When the trio first enters the cave, Soos lets go of the beaver and it lands onto the floor, but in the next scene, it disappears.
 * As Soos scoops fish food into the water, his arm disappears just before the boat drives off.
 * When the boat drives through the glass pane, the robot Gobblewonker disappears until Soos, Dipper, and Mabel are about to crash in the cave.

Headhunters

 * Wax Larry is first shown to be the same height as Wax Sherlock Holmes, but in the next scene he is much shorter.
 * Mabel's drawings of her sculpture ideas had color, but she was using a regular pencil.
 * Deputy Durland says 'Derp' without moving his mouth.
 * Shandra Jimenez is not at the re-opening of the Wax Museum, but she is there when Mabel calls on her for questions.
 * When Grunkle Stan left to use the bathroom, the lights were on, but when he came back, the lights were off.
 * The footprints left holes in the shag carpet the pushed down into the carpet. If the shoe had a hole in it, the carpet fabric would push up into the shoe.
 * Grunkle Stan's eyes are white when he says "Thank you all for coming".
 * Some of the footprints that are supposed to have holes in them don't have holes.
 * When Blubs and Durland checked the axe for fingerprints, they would have found Soos, Dipper, and Mabel's prints because they each touched it earlier.
 * When the security footage of Toby is shown the first time it starts at 10:00 and the seconds are at 1. But the second time it is shown, the seconds are back at 0 and the clock still says 10:00.
 * All of the wax figures have the hole in their shoe on the right. The ones on the carpet show a hole on the left.
 * The wax figures' unveiling is outside in broad daylight, but the figures don't melt.
 * The wax figures say they come alive during a waxing moon, but the moon shown during the fight between Dipper and Wax Sherlock Holmes is waning.
 * Toby Determined had a picture of wax Grunkle Stan's head, despite it being missing at the time.
 * When Grunkle Stan leaves to use the bathroom, Wax Stan has a stand. Yet, when he is on the ground, the stand is missing.
 * Manly Dan's name is misspelled as "Manley Dan" in Dipper's list of suspects.
 * Wax Robin Hood's bow switches from having an arrow to nothing.
 * In the scene where Mabel says, "Are you saying you could outwit Duck-tective?", before she says her line, her eyebrows and eyelashes are missing. Even her headband is now transparent.
 * In the flashback when Dipper explains why Toby Determined was the murderer, Toby's left shoe had the hole inside. But when they show the footprints, the hole was in the right shoe and earlier it was in the left shoe when they looked on the carpet.
 * In the flashback where Wax Sherlock Holmes decapitates Wax Stan, he appears to be sitting down because his legs are bent. When Wax Stan falls, he is standing up again.
 * Grunkle Stan says "Wax John Wilkes Booth, I'm looking at your direction!" although there is no wax figure of John Wilkes Booth.

The Hand That Rocks the Mabel

 * When 'Lil Gideon touches his amulet as he forces the crowd to stand, it doesn't glow like it does in all the other scenes of the episode when he touches it. This may have been to keep the amulet's powers a secret until later in the episode.
 * In the first shot of Officer Blubs, he has loads of 'Lil Gideon merchandise. But in the next shot, he only has the Gideon T-shirt.
 * Before Mabel shows her makeover to Dipper, Dipper's book has a 2 instead of a 3. The book labeled 2 belongs to 'Lil Gideon, making this impossible.
 * When Mabel complains that Dipper never does girly stuff with her, we see the book he was reading resting on the arm of the chair, but when Soos shows up with the hot dogs, it disappears.
 * In the close-up when Mabel is playing a video game with Dipper, the collar on her sweater has stripes. In all the other shots, it did not.
 * When Dipper and Mabel are playing with Soos, Mabel is wearing a sea-foam green-colored headband, but when Dipper hears the phone ring, her headband changes to red, then back to sea-foam green.
 * When Mabel blinks, the "bezazzles" on her right eye fall off, but they later return.
 * When Mabel coughs up "bezazzles" on 'Lil Gideon's jacket, they stick to it. But in the next shot, the jewels are gone.
 * While Mabel is on the boat with Gideon, she is wearing a headband, but when she gets back home, she is wearing a hair clip.
 * When Grunkle Stan runs away with the clown picture, one of his legs are missing.
 * After Dipper and Mabel are sitting on the couch, when Grunkle Stan talks to them, the umbrella on Mabel's sweater is gone. In the next frame, you can see part of the umbrella.
 * During the end credits Soos, Mabel and Dipper are using a flashlight, but it did not cast a shadow.
 * Also during the end credits, when Soos spins to the side with no jewels on it, the wall still has the disco ball effect.
 * Again, during the end credits, the light reflections rotate in the opposite direction Soos is spinning.
 * Once again during the ends credits, you can clearly see the colored lights repeatedly cover Mabel's face but not Dipper's.
 * Again in the end credits, Mabel's 'bezazzling' gun is not shown.
 * When 'Lil Gideon and Mabel are on the factory together, the factory switches between having an elevated roof in the background to have no elevated roof at all.
 * When 'Lil Gideon and Mabel are on their date, we never see Mabel's glass filled with water and yet when the waiter leaves, it is full of water.
 * Also, a few seconds before the waiter leaves, you can see the water full, but it has no bubbles.
 * Before we see Gideon and Mabel close-up on the boat, you can't see her headband.
 * When Gideon is rubbing Mabel's hair, it's not behind her ear, but when she slaps his hand away, her hair is like it usually is.
 * The website entitles the episode "The Hand That Rocks" as opposed to its full title.
 * When Mabel comes back from Gideon's dressing room with her makeover done. Mabel doesn't have any eyebrows in that scene.
 * At the "Club Club" restaurant, Mabel wears the same outfit she wore to the ballroom dance the previous night.

The Inconveniencing

 * When Dipper is trying to climb over the fence, Lee is on the same side as everyone else, the same side as Dusk2Dawn, but before he pushes Dipper off, he seems to be climbing from the outermost side of the fence, as if he was going in.
 * If the store was actually condemned, it is unlikely there would still be food there. Also, Dipper saw a newspaper that was dated back to 1995, meaning all the food would be expired and unsafe to eat.
 * In the scene when the first arrive Dipper goes to get the newspaper, When the newspaper is on the stand,the title reads USA WEEK but when Dipper rubs of the dust, the title now says NEWZ.
 * If the store had been closed for years with the power off, then the ice they got from the freezer would have just been bags of water.
 * When the three teens' reflections are shown in the window as normal, Tambry is smiling instead of just staring.
 * In the same scene, Tambry's leggings disappear.
 * Ma and Pa collapse from heart attacks by the window near the front door, but their bodies are chalked near the end of the store.S1e5_thompson_car_02.png
 * In the chalk outline, Ma's arms are sprawled out but when they show her collapsed in the flashback her arms are on her chest.
 * Robbie was the only teen besides Wendy that did not get turned into anything and he vanished when Wendy and Dipper were lifted onto the ceiling, and appears again when the ghosts let them go.
 * When the two were lifted onto the ceiling, the hot dog machine was not turning the hot dogs.
 * One of the "normal teenage things" that causes the ghosts to get angry is texting, but in 1995, texting was not considered a "normal teenage thing."
 * Tambry is not spotted in the minivan when Thompson drives the "gang" to Dusk 2 Dawn, even when there was a seat next to Mabel and Dipper.
 * When Wendy is telling everyone about how Dipper saved them, the mud on her boots is at the top, but when it shows her again the mud is on the bottom of her boots. In the same scene, Dipper has a peach-colored nose instead of a red one.
 * Thompson parks the minivan outside the fence when they arrive, but when Pa (speaking through Mabel) opens the doors, the minivan is inside the fence. When they get out, the minivan is outside the fence again.
 * In the scene when Dipper is opening the vent to get inside, Tambry's leggings briefly vanish again.
 * The open and closed sign changes from open to closed many times in different scenes.
 * When Dipper does the Lamby Lamby Dance, Ma's name tag is on her shirt, but when he finishes, it is gone.(
 * When Thompson was trapped in Dancy Pants Revolution, all the arrows that pierced him did not go to their proper color.
 * Early in the episode Mabel calls Dipper's dance "The Lamby Dance", but later on, Dipper calls it "The Lamby Lamby Dance".
 * When Dipper is seen with his clipboard from far away, his pen is in his left hand. Shortly after, it switches to his right, and then back to his left in the next shot.

Dipper vs. Manliness

 * When Sheriff Blubs is eating pancakes, he is almost done, but when it shows the number of pancakes then back the Sheriff Blubs, it starts from top again.
 * When Dipper is first seen walking down the street, the fire hydrant was fine and Sheriff Blubs and Deputy Durland weren't anywhere around it.
 * Dipper's beef jerky is also nowhere to be seen, but later appears in his hand.
 * When the animals are running away in the forest Dipper's hat disappears then appears in the next scene.
 * Mabel couldn't have seen Dipper's chest hair because his shirt would have covered it.
 * When Soos runs out the door, the door moves a little and then stops, but the style of the door and its position could not let it do that.
 * When Mabel gets an idea Soos's shirt is pink but when Mabel gets up his shirt is back to normal.
 * In the background of the diner, at one point the sign on the manliness test is misspelled as "manliess". It goes back to normal by the next scene.
 * One of the Manotaurs claims he has fists for nipples, but before and after they are shown, they disappear.
 * When Dipper is saying that the Manliness Tester was broken, everyone in the background are exactly still and don't even blink.
 * In the hot tub scene, when Dipper thanks the Manotaurs for teaching him to be a man, there are two manotaurs in the back round but they disappear when one of the manotaurs tells him of his last task.

Double Dipper

 * When Stan answers Soos' question about whose birthday it is, his bow-tie disappears.
 * Dipper says the first thing on his list is to talk with Wendy, but later it shows "smile" instead of talking.
 * Dipper says he has to follow steps 1-11, even though there are 20 steps.
 * Some of the people from inside of the party reappear in the the line by the ticket stand.
 * In the line when kids start waving around their arms to pay in cash to Wendy, one of kids near the front doesn't. As consequence, he has missing arms.
 * When Pacifica Northwest comes out of the bathroom, her colors are faded.
 * In several of the shots, the writing on Dipper's Plan is gone.
 * When Dipper and Wendy cheer, Dipper picks up his soda on the floor but he did not bring a soda in the hallway in the first place. Also, when the cup was on the ground before Wendy and Dipper cheer, nothing spilled so there was no soda. When the clones confronted Dipper, he dropped the cup and soda spills out.
 * When Dipper is talking to Wendy outside the bathroom, Wendy says "that guy" would be the leader of the island. They cut to a shot of "that guy" and Pacifica is near him on the dance floor. Moments later, she emerges from the bathroom.
 * Dipper sets off the fire sprinklers with smoke from a party popper. However, fire sprinklers are activated by heat, not smoke.
 * The red spreader stick in the crackers and cheese snack is not visible in the package, but it appears in Dipper's hand later.
 * When Mabel was dancing, there was a chair next to Candy Chiu but in the next scene, when she sat down to drink water, the chair disappeared.
 * When Dipper is on his way to ask Wendy to dance, he sees her and tells her she should be on the dance floor in exactly 42 seconds looking at a watch on his wrist, but the watch disappears after that.
 * When Mabel sprays her silly string at Dipper in the copier room, the string comes out of the side instead of the nozzle.
 * When Dipper drops his spray deodorant, the appearance of the can changes.
 * When Wendy tells Dipper she and Robbie are sitting on the couch her bow tie is missing, and later it reappears.
 * In the part where Dipper is reaching for his body spray, there is no blue jar on the case. Later, a blue can appears.
 * Soos said Robbie's dirt bike was being stolen, though it was actually a regular bike.
 * In the scene when Mabel says "Now's your chance to dance with Wendy!" Dipper pulls out his plan. Here, it seems smaller than other times we see it. Several times in the episode this happens again with all the clones.
 * When the Dipper clones confront "Dipper Classic" while Wendy was in the bathroom, the copies of "Wendy Plan B" are the same as the first plan.
 * In the scene where Tyrone and Dipper says "We blew it man." Wendy is out on the couch with Robbie. But, we should have seen her exit the bathroom from when she entered it, or at least react to the Dipper clones.
 * When Dipper spills soda on the copied arm, it only covers half the arm but in the next scene all of it is covered.
 * The "Wendy Mix" plays way too early before Dipper 10 puts it in.
 * When Mabel was singing, one of the people cheering her on did not have an ending to their left sleeve and it covered his whole hand.
 * Tyrone's can has the Pitt Cola sign, a peach, and red stripes. But Dipper's can only has the Pitt Cola sign, and the peach.
 * When Dipper and Mabel are on the couch, they're covered in silly string, but when Mabel throws the Comedy Gold, they're perfectly clean.

Irrational Treasure

 * When Grunkle Stan says "I will break you, Little Man!" to Toby Determined, the line between his eyes (part of his glasses) disappears.
 * When Sheriff Blubs is speaking into the microphone saying that the speech will begin, the microphone is there. When it zooms in a little bit, it is gone. But in the next scene where Pacifica is speaking, the microphone reappears.
 * Pacifica pulls the pen and paper out of nowhere when she hands it to Stan.
 * The pen in Grunkle Stan's mouth disappears after Pacifica reads the note he wrote.
 * When the twins exit the museum, the right hand door is open, however when the officers leave, the other door is the only one open.
 * When Dipper is going through the slides in the library, one is entitled "Numerology", but contains astrological symbols.
 * Mabel's mouth doesn't move when she laughs when Dipper says to look out for "booby traps".
 * Trembley says "and then he spanked me with a paddle for like, 3 hours" but people didn't say the word "like" in this fashion in the 1800s.
 * In the video, they cover the picture of Quentin Trembley with a picture of William Henry Harrison. Above Trembley's picture it says "8th President" even though he succeeded the 8th president. The picture shows above that he is the 9th president when the video is about to end.
 * In the top secret document that reveals Quentin Trembley as the founder of Gravity Falls, in the second paragraph, the "Falls" in "Gravity Falls" isn't capitalized.
 * In the document, it says there are 6 babies, but on-screen, there are only 4.
 * While watching the video, Mabel's eyebrows raise in surprise at the revelation that Quentin Trembley was once president. Her expression then shifts to confusion and her left eyebrow curves down onto her eye, but the surprised eyebrow is still on her face, giving her three eyebrows.
 * When the twins and Trembley climb the ladder to the top of the train, they are in the rear car. However, when they emerge on the top of the train, there are more train cars behind them.
 * While Dipper and Mabel read about the conspiracy in front of the statue, the bottom of Dipper's shoes change from white to black.
 * When Quentin Trembley is inside the block of peanut brittle, his expression changes throughout different scenes.
 * When Dipper is running towards Pacifica to tell her about Quentin Trembley, Mabel's headband disappears.
 * Quentin Trembley claims George Washington chased him around and spanked him, however George Washington would have either been dead or too old to chase Trembley at the time Trembley was president.

The Time Traveler's Pig

 * Blendin Blandin's watch switches hands when he is confronted by Mabel and Dipper.
 * Dipper's question mark corn dog disappears when Robbie shows up.
 * The caramel apple Mabel feeds Waddles disappears after she drops it.
 * The flash of light caused by Blendin's time machine in the credits during the events of "Headhunters" is not featured in the actual episode.
 * When Blendin's "position was compromised" after he failed to hide, his watch switched from his left hand to his right hand.
 * After Mabel hands Blendin tickets to the fair and he leaves, Mabel turns to the side, and her flower has vanished.
 * When Mabel loses her flower, it is on the other side on her head.
 * When Waddles is dressed as a doctor and follows Mabel to Blendin, his clothes disappear.
 * When Blendin walks to the barrel ride, the time machine is not on his belt. When the camera zooms in, it is.
 * The first time Dipper plays the ball toss, Robbie comes 10 or 20 seconds after Wendy gets a black eye, but many times while Dipper "do-overs" with the time machine Robbie comes earlier or right away sometimes even coming at a different direction.
 * In one of the scenes where Dipper and Mabel are talking to Blendin, Mabel's eyebrows disappear.
 * When Robbie talks to Wendy in Dipper's final do-over, there is a frame in which his teeth are skin-color as opposed to white.
 * When Dundgren is talking to Blendin, there is a frame in which his pupil is colored light green instead of black.
 * When Dipper and Mabel travel back in time to the episode "Headhunters", you see the pizza shirt guy wearing a green shirt, but in the actual episode, his shirt is red.
 * When Mabel is riding the ferris wheel with Waddles the ticket booth in front of the ferris wheel is facing to the right. In all the other "do-overs," it is facing toward the front.
 * When Wendy first sees the stuffed animals, they are seated on a board, but when they walk up, and the rest of the time, they appear to be dangling.
 * When Dipper goes back in time to get Waddles back for Mabel, she remembers everything that happened even though she did not travel back in time with him.
 * In the final reality, Blendin confronts Mabel and Dipper, but he didn't go with them and wouldn't remember it.
 * When Grunkle Stan laughs at Robbie, his finger leaves the border of the dunk tank.
 * When Mabel sat on the Test Your Strength game, the marker did not move when she got off, but it should have gone to 0 since it is impossible for Mabel to weigh 0 pounds.
 * When Soos tells Blendin to take of his belt because of "tools", the only thing it holds is his time machine.
 * When Mabel was playing with "Doctor Waddles", his nose color briefly changes.
 * In one scene, Robbie's teeth are pink.

Fight Fighters

 * When Wendy and Robbie were playing the game they were moving the joy stick and pressing the buttons, but in the next scene, if you look closely, there is nothing happening in the game.
 * When Rumble McSkirmish came out of the video game he slammed his fist down causing cracks in the ground, but in the next shot, they were gone.
 * When Mabel wins the crackers in the card game, nobody else had any. However, in the next scene, Dipper and Grunkle Stan both have more crackers.
 * When Robbie pushes Dipper down and then walks away, the trash cans and Dipper's hat disappear. They then reappear when Grunkle Stan comes out.
 * Also when Robbie walks away, his cellphone and amp are gone.
 * When Mabel puts on her 'scout's honor' sweater, her skirt and headband turn blue.
 * When Robbie was on the Water Tower, Rumble looked up at him to see where he was, but when Dipper was on top of a tree, Rumble said he didn't have "a looking-up animation", even though he looked up at Robbie a few scenes back.
 * Rumble said that he couldn't stay still, but when Mabel meets him, she hands him the paper with words for him to say, and he stays perfectly still and constantly stays still when talking to Dipper.
 * When Dipper is following the instructions "to unleash ultimate power", he doesn't execute the full code.
 * When Grunkle Stan falls backwards away from the TV, he falls on the floor. However, the wall is supposed to be closer to the dinosaur skull than it was in the aforementioned scene.
 * When Dipper is at the arcade and looks at the posters of Robbie, his watch disappears, but then later reappears.
 * When Rumble is on the floor, his eye patch keeps changing which eye it covers.
 * When Dipper was fighting Rumble, he shot a blue orb. In the scene right after, it's red.
 * In some scenes Robbie has five fingers while in others he has four.
 * When Rumble and Robbie are fighting, a poster for Robbie's band appears on the tree behind Dipper and Rumble, after Rumble wins.
 * As Grunkle Stan complains that, "[Mabel] doesn't even know what [they're] playing", Mabel's mouth closes without any animation.

Little Dipper

 * The Gummy Koala candy bag had a net weight of 5.29, but later, it reads that the net weight is 6.29.
 * When Gideon grabs the contract, the front of it is faced towards Stan. In the next scene, the paper switches to the other side without Gideon moving his hand.
 * When Grunkle Stan knocks the jar of termites out of Gideon's hands, it falls on the porch. When Gideon runs away, it is in the doorway.
 * When Dipper and Mabel are playing chess, Dipper tells Mabel that black isn't her color. When Dipper checkmates Mabel he moves the white pawn to knock over Mabel's black king.
 * Dipper grows the pawn while it is on the chess board, but later, it is shown in the background, out-of-place.
 * When Dipper and Mabel are fighting over the flashlight, the caterpillar ran over a couple of cars but when Dipper and Mabel drop the flashlight the cars are gone.
 * The Mystery Shack model is on the left side of Gideon's desk in the beginning. Later, Gideon closes his book and it is on the right side of his desk.
 * The photo of Gideon on his ID card shows him with only four fingers per hand.
 * When Mabel charges into her room, the closet door is open. But when she suspects a wizard made Dipper taller, she looks in the closet and has to open the door even though it was open and not tampered with when she arrived.
 * When Dipper and Mabel tickle Gideon, the pine tree on Dipper's hat is missing.
 * When Dipper shrunk, his hat shrunk with him. But when Soos shrunk, the fez hat doesn't shrink with him.
 * When Mabel was in the bag Gideon put her in gummy koalas it showed Mabel without a headband. Later it came out in the bag.
 * When Gideon was playing with the flashlight before he shrunk the twins, it's hard to notice but it was making the grow sound effect.
 * When Gideon is running away from the termites, he leaves the jar they were in at the shack. However, when he shrunk Dipper and Mabel, he has the jar again.
 * Dipper and Mabel are not visible in the jar when he turns to face his dad.
 * During the flashlight duel, Mabel and Dipper do not flick the crystal, but the beams change.

Summerween

 * When Stan pulls up to the Summerween Superstore, he parks in front of a handicap parking sign.S1e12_stans_car.png However, the sign is facing away from the parking spot instead of toward it.
 * When Mabel opens the door for the Summerween Trickster, Dipper was standing near. However the door never hit Dipper, nor was he there after, but appears later on.
 * In Mabel and Dipper's music number for Halloween at the biker's house, the treat bag disappears. When he gives them the candy, after it ended, it reappears in their hands.
 * During a few frames, the strawberry on Mabel's costume leaned in a different direction.
 * When Soos' truck was recklessly driving through town, it had a blanket draped on the back end of the car. After the car crashed into the store, it disappears.
 * When Soos hits the Summerween Trickster with his truck, Gorney can not be seen. But in the store when Soos is eating out of the Summerween Trickster, Gorney comes out.
 * In the Summerween Superstore, the skulls in the bowls are in different areas when they first get there and when Soos crashes his truck into the store.
 * In one of the opening frames, the lettering on the water tower that usually reads "Gravity Falls" is gone. Also, the walkway where Mabel took Grunkle Stan in the previous episode(s) isn't there.S1e12_water_tower.png
 * When Candy says she took a picture of the Summerween Trickster, she never pulls her phone out when she first met him.
 * Waddles has a light brown/tan spot on his left eye rather than his right eye.
 * When you first see children Trick-or-Treating, Waddles is with a random child, Candy and Grenda walking by themselves, and Gorney appearing on the top-left even when he was eaten.
 * The Summerween Trickster's eyes are peppermints, but after when Soos was eating him and he was screaming in pain and he fell on the ground his eyes are just yellow dots.
 * When Dipper is shocked to see Wendy with Robbie, he drops some candy from the bowl on the ground. When Wendy comes in the Mystery Shack with Robbie to get her jacket, no candy is seen on the floor.
 * In the promo for this episode, the Summerween Trickster is bright purple, but in the actual episode, he is dark purple.
 * When the Summerween Trickster is talking about "every discarded bar of chocolate with that white, powdery stuff" he's explaining it with both hands, even though he only had one free hand.
 * The Summerween Trickster said Dipper, Mabel, Candy, and Grenda had until the last jack-o-melon goes out to get 500 pieces of candy. Yet when the Summerween Trickster came to get his candy, Stan's jack-o-melon was still lit.
 * Twice in the episode, the Summerween Trickster shows its mouth: when he eats Gorney and when he is searching for Dipper, Mabel, Candy, Grenda, and Soos. However, when the Trickster reveals his full face, his mouth was under his mask.
 * When the Summerween Trickster first goes into the store for the kids, he tears the door off of Soos's car. When it shows the kids running around behind the Trickster, the car still has the door.
 * Dipper's watch disappears when he first opens the door to the Summerween Trickster then re-appears when Dipper closes the door.
 * Waddles's light brown/tan spot has been replaced with pink spots instead of light brown/tan spots, when he's eating the candy in a bowl.
 * Waddles' fake suit is stiff when he first appears; but later it folds when he goes to eat candy.

Boss Mabel

 * The episode took way too long to air.