Scooby-Doo, Where Are You! (1969)

S01E03 Hassle in the Castle

The group finds themselves stranded on an island that once served as a hideout for a notorious pirate. While exploring, they stumble upon a treasure map, but it comes with a cautionary message urging them to leave immediately. Their decision to stay proves perilous when they realize a ghost known as 'The Phantom' is hunting them down.