Bedlam in the Big Top - S1-E10
Continuity mistake: After meeting Mr. Barnstorm, Fred is driving the Mystery Machine from the passenger side, but the next shot from the front view shows Fred driving from the left (driver's) side.
Bedlam in the Big Top - S1-E10
Continuity mistake: Mr. Barnstorm is close in with the gang looking at the ghost clown in the cage, but the next shot shows Mr. Barnstorm alone.
Bedlam in the Big Top - S1-E10
Revealing mistake: The clown's left leg goes through the solid wood floor of the wagon as he flies into it.
Bedlam in the Big Top - S1-E10
Continuity mistake: The baggage on the back of Samson's tandem bike change colors as the scene plays out.
Bedlam in the Big Top - S1-E10
Continuity mistake: The darts the clown throws at the balloons disappear after popping a balloon.
Bedlam in the Big Top - S1-E10
Revealing mistake: Velma climbs the ladder without her hands grasping the rungs.
A Gaggle of Galloping Ghosts - S1-E11
Audio problem: The Frankenstein monster growls like the werewolf at one point in the laboratory.
A Gaggle of Galloping Ghosts - S1-E11
Continuity mistake: The Frankenstein monster suddenly appears outside the pantry door after Scooby opens the door - the monster did not walk out, but just appeared.
A Gaggle of Galloping Ghosts - S1-E11
Continuity mistake: In the Mystery Machine, Daphne is seated close to Fred, but the next shot shows her alone.
Scooby-Doo and a Mummy Too! - S1-E12
Plot hole: If the guilty man knew the diamond scarab was in the hippo statue then there's no reason he couldn't have broken the statue open and taken it.
Continuity mistake: When the gang 1st arrives at the beach. Fred stops the Mystery Machine. Although the van is stopped. The next shot shows Fred still sitting at the wheel, turning it, as if he is steering.
A Night of Fright is No Delight - S1-E16
Revealing mistake: When Scooby and Shaggy are on the bicycle with the Green Ghosts, the Ghosts' chains are missing.
A Night of Fright is No Delight - S1-E16
Other mistake: Velma asks Shaggy "How'd you get that green stuff on your hands?" but there is no visible "green stuff."
A Night of Fright is No Delight - S1-E16
Revealing mistake: When Scooby, Shaggy and Velma are on the drainpipe, it breaks and throws them into a cave. But the drainpipe hits the ocean like it is glass.
A Night of Fright is No Delight - S1-E16
Continuity mistake: When Scooby and Shaggy pull the corks on the bottles on the wine rack, the rack holds four bottles on each row, but when Shaggy runs off, there are now three bottles per row.
A Night of Fright is No Delight - S1-E16
Continuity mistake: When the gang meet up and Daphne says that they've got rid of the ghosts, there is a stand behind them, but in a close-up of Velma and Shaggy, a blue chair appears and there is now a candle holder on the wall.
A Night of Fright is No Delight - S1-E16
Continuity mistake: When we first see Scooby with Shaggy at the beginning of the episode, Scooby's collar tag has a blue diamond on it. When we see Scooby a little later on, the diamond has changed to "SD."
A Night of Fright is No Delight - S1-E16
Continuity mistake: In a full view of the gang on the boat at the beginning of the episode, Velma is reading a newspaper and behind her is Daphne, Scooby and Shaggy. But in a close-up of Velma in the next shot, they have all disappeared.
A Night of Fright is No Delight - S1-E16
Continuity mistake: When Creeps plays the record, it is placed on a phonogram on a table. But after the message has finished, Creeps is holding the record but the phonogram and table are nowhere to be seen.
A Night of Fright is No Delight - S1-E16
Continuity mistake: When Shaggy takes out his sandwich, the goldfish bowl next to him is empty. When he grabs the box of fish food, the bowl now has water and a goldfish in it.
Chosen answer: A ghost wouldn't have to keep any food in the fridge - they don't need to eat. So it is one thing that proves the ghost is not a ghost.