The Night Ghoul of WonderworldGoofs

When the Night Ghoul is unmasked, Velma mentions one of the clues was the fact that the culprit had earlier specifically mentioned the theft of the crown jewels - something he should not have known about. However, no such thing was mentioned by him in the scene in question.

In the final scene, Velma calls Mr. Marino 'Mr. Marina'.

At the commercial break cliffhanger, the Night Ghoul rises from a manhole that Scrappy is standing on to which Scrappy says 'He found us Uncle Scooby' to which Shaggy responds with the contradiction 'Like I think HE found us!'. This makes no sense as Shaggy contradicted Scrappy with the exact same thing. It appears Scrappy's original line was intended to be 'We found him Uncle Scooby!'.