The Hairy Scare of the Devil Bear - S1-E8
Character mistake: Velma says bears only have four claws. Wrong, they really do have five claws.
Scooby-Doo and Scrappy-Doo (1979)
1 character mistake - chronological order
Starring: Don Messick, Casey Kasem, Lennie Weinrib, Heather North
Continuity mistake: When Scooby and Shaggy are at the "Hotus Dogus" stand in the Coliseum, you can see that Scooby has two flags in his left hand, but after a quick close-up of Scooby, we return to him and his flags have disappeared.