this show start out with great mystery episode . i think everyone be in the first 15 or 16 episode . after that and the show start play short episode with shaggy and scooby doo and and scrappy doo . i think hanna barbera production have to change 20 minute episodes into short episode . some of the voice actor become unavailable . after 15 or 16 episode and frank welker ( who play fred ) become unavailable . i think the voice of velma change after first 12 episode and because the first voice actress who play velma be unavailable . and the network order the hanna barbera studio to make more short with shaggy and scooby doo and and scrappy doo and because the rating be high . so they have to make more short . i wish they be mystery like 15 episode . still it be a good show .