Finn

Jeremy Shada

Jake

John DiMaggio

Princess Bubblegum

Hynden Walch

The Ice King

Tom Kenny

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

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

Marceline the Vampire Queen (voice)

Olivia Olson

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

Lumpy Space Princess/Nipple Guy

Pendleton Ward

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

Young Marceline (voice) / Candy Kids (voice) / Young Marceline

Ava Acres

Cloud Groom

John Kassir

Earl of Lemongrab (voice) / Lemongrab 2 (voice) / Lemonpink (voice)

Justin Roiland

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 (voice)

Madeleine Martin

Cake (voice)

Roz Ryan

Jake Jr (voice)

Kristen Schaal

Tv (voice)

Dan Mintz

Young Princess Bubblegum (voice)

Isabella Acres

Banana Man (voice)

'Weird Al' Yankovic

Party Pat / Rap Bear (voice) / Party Pat (voice)

Andy Samberg