It's All Greek to Scooby - S2-E13
Continuity mistake: Lysander digs through the box of jewelry frantically trying to find the medallion that was slapped away from him. After the merchant says he sold it to Shaggy, the box is shown again and the arraignment of the jewelry changes back to about how it was before he dug through it. (00:04:25)
Continuity mistake: The gang investigates the trail of limestone to a manhole in the middle of the street, with nothing around it. But when Daphne is putting on her "Wallowing galoshes" boots, somehow a small brick wall just materializes in the middle of the street for her to sit on - and then vanishes a couple shots later. Not just the fact that it appears and vanishes between shots, but that there is a random brick wall in the middle of the road. (00:05:10)
Large Dragon at Large - S2-E10
Continuity mistake: Velma and Daphne are sitting on a bench, with Velma on the left and Daphne on the right. When they hear Shaggy and Scooby screaming they quickly stand up and the shot changes to show them running past the girls. The bench they were sitting on vanishes, and the girls switch places. (00:05:00)
It's All Greek to Scooby - S2-E13
Continuity mistake: After the Centaur falls of the scaffoldings, Fred, Daphne and Velma climb up and are seen standing straight up while Shaggy is putting the medallion back in his shirt. It cuts to just show them and suddenly Fred has his hands on his hips, Daphne is dusting herself off, and Velma is bent over trying to catch her breath. (00:06:15)
Large Dragon at Large - S2-E10
Continuity mistake: As Shaggy is handing Scooby a tower of food, he has one hand on each tower at the bottom, and Scooby reaches out with just one paw to take it while Shaggy is speaking. Before Shaggy finishes his sentence, it cuts to a close up while Scooby is touching his tower, and suddenly Shaggy is only holding his tower with a hand on bottom and top, and Scooby is suddenly doing the same with his. (00:04:50)
Large Dragon at Large - S2-E10
Continuity mistake: As the gang are walking through a market like area, Shaggy says "Like, I can't believe we came all the way to Scotland for a renaissance fair." As he does, the shot changes and suddenly he, Fred, Scooby, and Daphne are looking to their right, when they were all looking straight in the previous shot. The group's arrangement also changes from more scattered, to being in basically a straight line side to side. (00:02:10)
Pompeii and Circumstance - S1-E12
Continuity mistake: When Captain Guzman puts the artifact into a chest, Scooby quickly sniffs around inside and then has the lid almost slammed on his nose. Scooby jumps up quickly and holds his nose in shock. The shot changes and suddenly Scooby is a considerable distance away from the chest. (00:14:00)
Pompeii and Circumstance - S1-E12
Continuity mistake: When the Gladiator Zombie is chasing the Mystery Gang in the golf cart, he flicks his whip at them. Scooby is seen on the left side of the back seat looking out and covers his eyes. The very next shot, Scooby is suddenly on the right side of the seat looking forward. (00:09:15)
Pompeii and Circumstance - S1-E12
Continuity mistake: It is Daphne who swoops in with the golf cart and saves the gang from the Gladiator zombie. Yet moments later, Fred is driving. Ironically while thanking her for saving them. (00:09:00)
Pompeii and Circumstance - S1-E12
Audio problem: When Daphne takes off in the golf cart after picking up the rest of the gang, it makes the sound of tires on pavement. But they are on the dirt floor of the Coliseum. (00:08:55)
Pompeii and Circumstance - S1-E12
Continuity mistake: As Daphne is talking about the old statues in the window, an Italian wearing glasses comes up and talks back, who has normal eyes. Just before it cuts away, he stops moving and suddenly the irises of his eyes are hollow, where the drawing was unfinished. (00:02:15)
Continuity mistake: In the opening title sequence, when the mummy appears behind the gang, you can see his red eyes. But in the next shot, his eyes are missing. (00:00:45)
Large Dragon at Large - S2-E10
Continuity mistake: As the dragon begins breaking down the house, the door is green and crumbles. The shot cuts to the two guys screaming and then back to the dragon. Now the broken door is brown. (00:01:55)
It's All Greek to Scooby - S2-E13
Continuity mistake: The gang catches a ride on a boat and have to find room in the animal storage area. Shaggy and Scooby are shown sleeping next to the sheep. But when Lysander walks in, they are next to the goat. (00:10:35)
Big Scare in the Big Easy - S1-E4
Continuity mistake: Crawdad Mike goes from having a full head of hair when he's unmasked as one of the ghosts to being bald on top in the next shot.
Other mistake: Fred's shadow isn't shown in the opening credits.
Suggested correction: Be more specific. What part of the opening credits?
When their shadows are black and going across the screen from right to left.
Continuity mistake: Shaggy's shoe keeps going from clean to covered with bat guano in several shots.
Large Dragon at Large - S2-E10
Continuity mistake: Lancelot's right glove controlled the dragon, but when Scooby's fooling around with it later it's on his left paw.
It's Mean, It's Green, It's the Mystery Machine - S1-E5
Continuity mistake: When the van crashes into a wall, the emblem falls off. In the drive in scene, the emblem magically reappears.
A Scooby-Doo Valentine - S3-E3
Plot hole: It's never explained how JC Chasez and the Hollywood extras impersonating the gang gained the super strength they possessed to do things like ripping car roofs open or holding up the Mystery Machine.