Shaggy's uncle Shagworthy disappears, so the gang go to his castle to investigate and learn that when he shipped the castle from the U.K., he also unwittingly imported a number of ghosts.
This episode includes examples of the following:
- Adaptational Villainy: Merlin is a lot more malicious here than his usual depiction as a protector and guide to King Arthur.
- Black Knight: Literally, as a knight in black armor is one of the villains. He turns out to be a henchman working for the man behind the ghost of Merlin.
- Brainwashed and Crazy: Merlin hypnotizes Shaggy and Scooby and orders them to kill the others. They aren't very successful, and their friends eventually figure out what happened and un-hypnotize them.
- Falling Chandelier of Doom: Subverted — while hypnotized, Shaggy drops one on Fred and the girls, but misses.
- Haunted Castle: Shaggy's Uncle Shagworthy has imported one to the States.
- Saw a Woman in Half: Stage magician Zarko does this on Scooby and Shaggy, only to get angry when they panic and end up running around in fright, causing the audience to boo him.
- "Scooby-Doo" Hoax: The villains, in their disguises as the ghost of Merlin and a black knight, are trying to scare everyone away so they can search for Uncle Shagworthy's jewels. (Which turn out to be in his refrigerator.)
- Shout-Out: Scooby attempts to do magic by spouting the magic words "Bibbidi-bobbidi-boo!"
- Strong Family Resemblance: Uncle Shagworthy looks almost exactly like Shaggy, except for his monocle and moustache. Velma lampshades the resemblance.
