Mine Your Own Business - S1-E4
Character mistake: When Shaggy and Scooby order Sarsaparilla at the saloon, Scooby says "Two" but he appears to be holding up three fingers.
Scooby-Doo, Where Are You! (1969)
1 character mistake in season 1
Starring: Frank Welker, Don Messick, Casey Kasem, Nicole Jaffe
Don't Fool With a Phantom - S2-E8
Continuity mistake: The gang find Jonny tied up in a chair and he says it wasn't a publicity stunt. Both his arms are tied up to his sides by the rope. It cuts from the close up to show them all again, and suddenly Jonny is holding his hand to his head and Fred is suddenly pulling on the rope, his arm outside of the rope. (00:02:45)
Shaggy: Scooby-Snacks won't work on me this time.
Daphne: Would you do it for a Shaggy-Snack? A little something I whipped up.
Shaggy: Huh? A Shaggy-Snack?
Daphne: Yes, it's a pot-pie, with pizza crust, anchovies, pepperoni, cherries, all in a thick chocolate sauce.
Shaggy: Hahahaha! I'll do it! I'll do it!
Scooby's Night With a Frozen Fright - S2-E4
Question: Is Daphne holding her breath when the gang is in the tank underwater?