Here are some options:
Individual Series:
* Scooby-Doo and Scrappy-Doo (1979-1980): This features the classic series where Scrappy first joined the gang.
* The New Scooby-Doo Mysteries (1984-1985): This series introduces the "new" Scrappy, who is somewhat different from the original.
Compilation DVDs:
* Scooby-Doo: The Complete Scooby & Scrappy-Doo Series: This set includes all episodes from the original series.
* Scooby-Doo on Zombie Island: While not exclusively featuring Scrappy, this film has a prominent role for him.
Other DVDs featuring Scrappy:
* Scooby-Doo on Zombie Island
* Scooby-Doo! Spooky Space Kook
* Scooby-Doo! Legend of the Phantosaur
You can usually find these DVDs on online retailers like Amazon or eBay.