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.
A Night of Fright is No Delight - S1-E16
Continuity mistake: When the goldfish snaps at Shaggy for taking his fish food, there are some rocks at the bottom of the bowl, but when Shaggy says "Sorry" and puts the box down, the rocks have disappeared.
A Night of Fright is No Delight - S1-E16
Continuity mistake: When Fred is reading his book in bed, he is wearing his pyjamas, but when Fred says "You got to be kidding", he is wearing his regular clothes, and when he, Scooby and Shaggy go back into the bathroom to inspect the bathtub, Fred is back in his pyjamas again.
A Night of Fright is No Delight - S1-E16
Continuity mistake: When the gang peek out of their rooms after hearing spooky noises from Cousin Simple's room, Fred is wearing his regular clothes, but in the next shot he is wearing his pyjamas.
A Night of Fright is No Delight - S1-E16
Continuity mistake: When Shaggy notices footprints in the ground in the cave, he is standing behind Velma, but in a close-up of Velma in the next shot, Shaggy has gone.
A Night of Fright is No Delight - S1-E16
Continuity mistake: When Velma tells Shaggy that they are going to follow the Phantom Shadow's footprints, her glasses have no lenses in them, but they re-appear in the next shot.
A Night of Fright is No Delight - S1-E16
Continuity mistake: When the flying uniform chases Scooby, Shaggy and Velma, the shoulder strap changes shoulder whenever the uniform changes direction.
A Night of Fright is No Delight - S1-E16
Continuity mistake: When Scooby, Shaggy and Velma go up the elevator, Velma operates it with a hand lever, but when they arrive at Cousin Slicker's room, the lever has gone.
A Night of Fright is No Delight - S1-E16
Continuity mistake: When the gang meet up and realise that all the heirs are missing, Daphne is behind Scooby, but in a close-up of Scooby in the next shot, she has disappeared.
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.