Continuity mistake: When Fred and Daphne arrive at a temple screen, the top lavender strip on Daphne's skirt is missing.
Continuity mistake: When we see Fred holding the picture of Champion in the Mystery Machine, he is holding one sheet of paper. When we see a full view of the gang in the next shot, Fred is now holding two sheets.
Continuity mistake: When Scooby is in Buck Masters' office, he sees a pointer dog on top of a stand and then does an impression of it by pointing his finger and freezes. When the camera closes in on Scooby in the next shot, the stand has disappeared.
Continuity mistake: When Scooby Doo rushes back on to the beach and Shaggy asks him, "What's with you?", Scooby's eyebrows disappear briefly.
Continuity mistake: In the shot of Scooby Doo turning on the radio at the beach, his spots are missing.
Continuity mistake: When the Mystery Machine is driving down Beach Boulevard, you can see Fred and Daphne are sitting in the front seat. When Velma locates Scooby-Doo on the radar using the transmitter in his collar, we cut to the Mystery Machine and Fred and Daphne have now gone.
A Gaggle of Galloping Ghosts - S1-E11
Audio problem: The Frankenstein monster growls like the werewolf at one point in the laboratory.
Plot hole: Given he fell down into a ravine it seems impossible for Carl to have got back to his trailer before Mystery Inc does.
Bedlam in the Big Top - S1-E10
Continuity mistake: Velma throws the umbrella to Scooby pointed end first, but when it arrives at Scooby, the umbrella is handle-end first.
Bedlam in the Big Top - S1-E10
Continuity mistake: After the umbrella turns inside out, Scooby loses his grip with the umbrella and falls to the trampoline, but the umbrella does not follow Scooby down.
Bedlam in the Big Top - S1-E10
Continuity mistake: The table behind Shaggy changes color several times as he performs the Lion Tamer act in the cage with the lion.
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.