Continuity: Just before Shaggy goes into the secret passage way, he sits on a stone, and his hair has somehow turned yellow.

Other: How did the make-up hide the bad guy's glasses?

Plot hole: Where did the Ape Man get the Scooby mask?

Continuity: 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.

Plot hole: It's established at the end that Greenway used transparent skis to create the illusion that the Snow Ghost could fly. But there's no way skis could have enabled Greenway to fly over the gorge, especially from a standing position.

Other: There is a scene where the gang is the home of the Bank President, just after dropping off the injured bank guard. At one point the Bank President is standing behind an end table of some kind with a lamp on it. Even though there is nothing underneath the table to block your view you cannot see the lower part of the Bank President's leg. It looks like it has been cut off.

Continuity: Just before the mask is pulled off the Creeper, Scooby's collar splits into two parts and then changes back again.