Guest Stars Jeff Bennett voices Choose Goose Hynden Walch voices Princess Bubblegum Steve Little voices Peppermint Butler Toks Olagundoye voices Dr. Caledonius Bex Taylor-Klaus voices Blaine Maurice LaMarche voices Skull Maurice LaMarche voices Wizard Cop #1 Anthony Stewart Head voices Con Wizard Tom Kenny voices Berdzerd Edi Patterson voices Momdebra Edi Patterson voices Cat Student Duncan Trussell voices Ron James Bill Hader voices Bufo Dana Snyder voices Potable Wizard Dana Snyder voices Life Giving Magus Julia Butters voices Larry Steve Little voices Abracadaniel Patti Harrison voices Weapon Head Chloe Coleman voices Cadebra SungWon Cho voices Brain Wizard Cole Sanchez voices Little Dude Sheng Wang voices Dimension Wizard John Omohundro voices Spader SungWon Cho voices Wizard Cop #2 Co Starring John DiMaggio voices Additional Voices Tom Kenny voices Additional Voices Jeremy Shada voices Additional Voices Pendleton Ward voices Additional Voices Niki Hyun Yang voices Additional Voices Cole Sanchez voices Additional Voices Jeff Bennett voices Additional Voices Bex Taylor-Klaus voices Additional Voices Julia Butters voices Additional Voices SungWon Cho voices Additional Voices