Suggestions by @kevindolan

John Cohen

as Producer in Garfield

Mark Dindal

as Director in Garfield

Bill Fagerbakke

as Patrick Star in The ABSOLUTE Perfect Crossover Movie

Maurice LaMarche

as Yosemite Sam in The ABSOLUTE Perfect Crossover Movie

Bob Bergen

as Porky Pig in The ABSOLUTE Perfect Crossover Movie

Eric Bauza

as Stimpy in The ABSOLUTE Perfect Crossover Movie

Frank Welker

as Scooby-Doo in Scoob!

Antonio Raul Garcia

as Casper the Friendly Ghost in Scooby Doo and Guess Who? (Potential New Episodes)

Cristela Alonzo

as Taffy Dare in Hanna Barbera Funtastic Universe

Paget Brewster

as Brenda Chance in Hanna Barbera Funtastic Universe

Amanda Seyfried

as Daphne Blake in Hanna Barbera Funtastic Universe

Zac Efron

as Fred Jones in Hanna Barbera Funtastic Universe

Gina Rodriguez

as Velma Dinkley in Hanna Barbera Funtastic Universe

Don Messick

as Muttley in Hanna Barbera Funtastic Universe

Mark Wahlberg

as Blue Falcon in Hanna Barbera Funtastic Universe

Tracy Morgan

as Captain Caveman in Hanna Barbera Funtastic Universe

Ken Jeong

as Dynomutt in Hanna Barbera Funtastic Universe

Kiersey Clemons

as Dee Dee Skyes in Hanna Barbera Funtastic Universe

Jason Isaacs

as Dick Dastardly in Hanna Barbera Funtastic Universe

Will Forte

as Norville Rogers in Hanna Barbera Funtastic Universe