Jack McBrayer
Wander (voice) (79 eps)
April Winchell
Sylvia (voice) (79 eps)
Keith Ferguson
Lord Hater (voice) (79 eps)
Tom Kenny
Peepers (voice) (79 eps)
Noël Wells
Dominator (voice) (40 eps)
Sam Riegel
Emperor Awesome (voice) (10 eps)
Fred Tatasciore
Pit Monster (voice) (8 eps)
Piotr Michael
Major Threat (voice) (4 eps)
James Marsden
Sir Brad Starlight (voice) (3 eps)
Rich Fulcher
Evil Sandwich (voice) (3 eps)
Jennifer Hale
Ripov (voice) (3 eps)
'Weird Al' Yankovic
Dr. Screwball Jones (voice) (2 eps)
Bill Fagerbakke
Prince Cashmere (voice) (2 eps)
Kevin Michael Richardson
Papa Doom (voice) (2 eps)
Jeff Bennett
Harvax (voice) (2 eps)
Genevieve Hannelius
Little Bits (voice) (2 eps)
Michael Croner
Obvious Teen (voice) (2 eps)
Seth Morris
Neckbeard (voice) (2 eps)
Sabrina Carpenter
Melodie (voice) (1 eps)
Rob Riggle
Bill (voice) (1 eps)
Ken Marino
Phil (voice) (1 eps)
Bryan Callen
Gil (voice) (1 eps)
Laraine Newman
Gram (voice) (1 eps)
Clancy Brown
Badlands Dan (voice) (1 eps)
Aziz Ansari
Westley (voice) (1 eps)
Tara Strong
Beeza (voice) (1 eps)
Corey Burton
Captain (voice) (1 eps)
Charlie Adler
Stok (voice) (1 eps)
Edie McClurg
Trudi (voice) (1 eps)
Kari Wahlgren
Janet (voice) (1 eps)
René Auberjonois
Maurice (voice) (1 eps)
Owen Faust
Huckleberry Knucklehead (voice) (1 eps)
Steve Blum
General Outrage (voice) (1 eps)
Dwight Schultz
Wild Card (voice) (1 eps)
John Hodgman
Lord of Illumination (voice) (1 eps)
Will Arnett
Ryder (voice) (1 eps)
June Squibb
Stella Starbella (voice) (1 eps)
Kevin McDonald
Sherblorg King (voice) (1 eps)
Andy Daly
Andy the Watchdog (voice) (1 eps)
Calum Worthy
Teen Leader (voice) (1 eps)
Josh Sussman
Weasly Teen (voice) (1 eps)
Jon Hamm
Cartoon Hater (voice) (1 eps)
Eddie Deezen
Cartoon Peepers (voice) (1 eps)
Frank Welker
Announcer (voice) (1 eps)
Jason Ritter
Skipper (voice) (1 eps)
Kristen Schaal
Mavis (voice) (1 eps)
Alex Hirsch
Old Man / Soosy Du (voice) (1 eps)
Sandy Martin
Dorothy (voice) (1 eps)
Lyons Mathias
David (voice) (1 eps)
Blake Bertrand
Jamie (voice) (1 eps)
Connor Wise
Hank (voice) (1 eps)
James Adomian
Glutteus Maximus (voice) (1 eps)
Andy Bean
Orbble Wright (voice) (1 eps)
Fuller Condon
Wilmur Wright (voice) (1 eps)
Dee Bradley Baker
Bittles (voice) (1 eps)
Daran Norris
Mittens (voice) (1 eps)
Craig McCracken
Destructor's Sock (voice) (1 eps)