The gang delivers a supposedly evil dummy, Crazy Karl, to a ventriloquism competition, and when they return to make sure everything went okay, they find that, true to form, they've got another mystery on their hands.
This episode includes examples of the following tropes:
- Borrowed Catch Phrase: At the end, it's Petunia who says (or rather, sings), "Scooby-Dooby-Doo!"
- Cassandra Truth: No matter how hard he tries, Shaggy can't get the guest stars to believe that Scooby is a Talking Animal and he's not using ventriloquism to put words in his mouth.
- Chekhov's Gun: At the hotel, Jeff spooks Shaggy and Scooby by remotely operating his dummy, Walter. That turns out to be part of the way Crazy Karl managed to move by "himself."
- Clingy MacGuffin: Scooby, freaked out by Crazy Karl, digs a hole and buries him. That night at the hotel, Crazy Karl comes back to torment Scooby and Shaggy in their room.
- Demonic Dummy: One of these, Crazy Karl, is the Villain of the Week. He looks like the Joker and is supposedly possessed by the ghost of a wicked ventriloquist. He also has telescoping limbs and a creepy voice.
- Huge Guy, Tiny Girl: The guest stars of the week are Jeff Dunham and Darci Lynn Farmer, an adult guy and a preadolescent girl. Naturally, the height difference is striking whenever they're in frame together.
- Music for Courage: Darci's puppet, Petunia, claims that she's shy except when she's singing. During one scene, she breaks out singing while they're trying to hide from creepy innkeepers.
- Red Herring: The innkeepers are creepy, collect dummies, and try to "kidnap" Petunia, but they aren't the villains of the week. They're interested in dolls and trying to create a museum.
- Self-Deprecation: Jeff Dunham says that Crazy Karl was once owned by the most evil ventriloquist who ever lived, at which point Walter turns and looks at him.
- Tempting Fate: While the gang are delivering Crazy Karl, somebody says that there's no way a dummy could cause any real trouble. Shaggy and Scooby comment that they hate it when someone says things like that, because something bad always happens afterwards. Sure enough, the dummy ends up at the center of a mystery.
