Frank Welker

Scooby-Doo / Fred Jones / Self

Matthew Lillard

Norville 'Shaggy' Rogers / Self - Voice of "Shaggy"

Grey DeLisle

Daphne Blake / Self - Voice of "Daphne"

Kate Micucci

Velma Dinkley / Self - Voice of "Velma"

Janel Parrish

Janel Parrish - Host

Jerry Beck

Self - Animation Historian and Author

David Silverman

Self - Director and Producer, "The Simpsons"

Seth Green

Self - Actor, "Scooby-Doo 2: Monsters Unleashed"

Tony Cervone

Self - Director, "Scoob!" / Showrunner, "Mystery Incorporated"

Tom Sito

Self - Animator, Historian

Joseph Barbera

Self - Hanna-Barbera Co-Founder (archive footage)

Mary Lynn Rajskub

Producer Bryn

Baron Vaughn

Bram Penobscot - Scooby's Vocal Coach

Casey Kasem

Shaggy Rogers (voice) (archive footage)

Diedrich Bader

Batman - Concerned Citizen (voice)

"Weird Al" Yankovic

Self - Singer, Songwriter, Accordionist

Olivia Liang

Olivia Liang - Shaggy's Martial Arts Trainer

Karamo Brown

Costume Designer Carter

Cheri Oteri

Lazlo the Mechanic

Brendan Jennings

Arlo Davidsonman - Team Scooby