RR Scooby-Doo and Scrappy-Doo

When Hanna-Barbera realized the Scooby-Doo formula was starting to get stale... they thought adding a younger pup would be the best way to revive the show...

Scooby-Doo - where are you?! Right here:

Scooby-Doo, Where Are You!
The 13 Ghosts of Scooby-Doo