Scooby-Doo! Mystery Incorporated/Trivia
- Hey, It's That Voice!:
- Matthew Lillard, the live action actor for the first two Scooby-Doo movies, provides the voice of Shaggy after Casey Kasem finally stepped down after a good 40 years.
- Azula, Mandy and Vicky playing pretty much their complete opposite in Daphne.
- And, as usual, Frank Welker is Fred.
- Joe Swanson, The Tick (animation), Puddy, Kronk, and Brock freakin Samson as the Sheriff.
- Casey Kasem, the original Shaggy, as his dad.
- LEWIS FRIGGIN' BLACK as Mr. E.
- Lloyd Irving is the younger version of Mr. E.
- You might recognize Professor Rockelow as Conrad Fleem.
- Harvey Birdman as Fred's dad.
- Frances Conroy and Kevin Dunn voice Velma's mom and dad. Mr. Dunn also provides voices for incidental characters, like the restaurant Maitre D' in episode 11.
- John O'Hurley is easily recognizable as Skipper.
- Vernita Green aka "Copperhead" as Angel Dynamite.
- Jennifer Hale is Daphne's Army soldier sister, Delilah, as well as reprising the role of Thorn.
- James Arnold Taylor as Rung Ladderton. It's certainly not the first time he's played a teenaged millionaire who turned out to be the mystery villian in a show directed by Victor Cook.
- Hynden Walch as Alice May in episode 6.
- Quinton Flynn shows up to pull double duty in episode 7, as the Hex Girls' manager Gus Boggs, and their stagehand Daniel Prezette.
- Lucille Bleuth as the mom of Velma's Stalker with a Crush Jason.
- Jason himself is Generator Rex.
- Maurice LaMarche as Vincent Van Ghoul. This is especially prominent in episode 19, where he does a cracker-jack imitation of legendary horror movie actor, Vincent Price.
- Udo Kier as Professor Pericles.
- Daphne's Mom is the mom of a certain redhead genius boy.
- Jeffrey Combs as Professor Hatecraft.
- Also in episode 12, Crispin Freeman is all over the place, playing just about every other male extra, as well as Prof. Hatecraft's assistant.
- In episode 17, Dwight Schulz portrays the last survivor of the long-vanished Darrow Family.
- Episode 18 has the gang face off against Mr Sulu himself.
- Also in episode 18, Mai Lee, Shaggy's love interest, is voiced by Stephanie Sheh, aka Hinata Hyugga.
- Chen is voiced by James Hong, who has played just about every middle-aged or older Chinese male in a Cartoon Network series since Teen Titans.
- Episode 21: Hot Dog Water is voiced by Linda Cardellini, who played Velma in the theatrical live-action Scooby movies.
- Episode 24: Florence Henderson voices Sheriff Stone's mother. Powers Boothe voices Dead Justice.
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