Finn
Jeremy Shada
Jake
John DiMaggio
Ice King (voice) / Flying Lettuce Brother (voice)
Tom Kenny
Princess Bubblegum
Hynden Walch
Lumpy Space Princess/Nipple Guy
Pendleton Ward
BMO / Lady Rainicorn (voice)
Niki Yang
Penny
Violet Sole Closs Farley
N.E.P.T.R.
Andy Milonakis
Billy
Lou Ferrigno
Ricardio
George Takei
Manish Man
Fred Tatasciore
Marceline the Vampire Queen (voice)
Olivia Olson
Gork/Two-Headed Monster Head 2
Michael Dorn
Old Lady Princess/Girl Bear/Swan
Kerri Kenny-Silver
Tree Trunks (voice)
Polly Lou Livingston
Peanut/Marquess of Nuts
Vincenzo Rauso
Keyper/Gnome 2
John Moschitta Jr.
Poor Lady/Fine Lady
Maria Bamford
Fear Feaster/Wizard
Mark Hamill
Wizard/Head 2/Phil
Ghostshrimp
Mr. Cream Puff/Mr. Cupcake/Chet
Dee Bradley Baker
Cobbler/Swamp Giant/Old Lady
Steve Little
Demon Cat/Evil Guy
Clancy Brown
Court Giant/King Worm
Erik Estrada
Turtle/Head 1/Guy 1
Kent Osborne
Business Man 1
Brian Posehn
Cookie Man
Henry Rollins
Eclair Boy
Jackie Buscarino
Butter Beans
Jacob Kepler
Donny/Dog House
Kevin Michael Richardson
Mountain Man/Marauder 5/Electroid
Matt Jones
Earl of Lemongrab (voice) / Lemongrab 2 (voice) / Starfish Martian (voice)
Justin Roiland
Cloud Groom
John Kassir
Young Marceline (voice) / Candy Kids (voice) / Jamaica (voice)
Ava Acres
Head Marauder/Cat Man/Coal Guy
Tom Wilson
Frog/Lenny/Ripped Lumpy
Keith Ferguson
Prismo (voice)
Kumail Nanjiani
Cuber (voice)
Emo Philips
Breezy (voice) / Blacksmith / Scorpion (voice)
Ashly Burch
Fionna
Madeleine Martin
Cake
Roz Ryan
Jake Jr (voice) / Jack Jr (voice)
Kristen Schaal
Tv (voice)
Dan Mintz
Banana Man
'Weird Al' Yankovic
Party Pat / Rap Bear / Party Splat
Andy Samberg
Prince Gumball
Neil Patrick Harris