Be Cool, Scooby-Doo! - Season 2 Episode 7 -

The gang visits a strange town on Halloween night to celebrate the holiday, but the festivities are soon interrupted when Shaggy and Scooby run into a witch's house while trick or treating. Much to the gang's surprise, Fred reveals that he ran into this same witch 11 years ago and has been afraid to solve a mystery on Halloween ever since. In the process of solving the mystery, the gang tries to convince Fred that it is possible to solve a mystery on Halloween night despite his superstitious belief.