Undertime

Main

 * Finn - Skull
 * Jake - Blackjack
 * Ice King -
 * Princess Bubblegum -
 * Lady Rainicorn - TinySatan
 * Marceline -
 * Lumpy Space Princess -
 * BMO -

Major/Recurring

 * Ash
 * Banana Man
 * Billy
 * Charlie
 * Choose Goose
 * Cinnamon Bun
 * Cosmic Owl
 * Death -
 * Doctor Princess
 * Flambo
 * Flame King
 * Flame Princess
 * Gumball Guardians
 * Gunter
 * Hunson Abadeer
 * Jake Jr. - Jay
 * Jermaine - Serif
 * Joshua - Tempah
 * Kim Kil Whan - Future Jay
 * Lemongrab
 * The Lich - Gothic
 * Magic Man
 * Margaret - Yananeska
 * Martin Mertins - Pacifist!Error
 * Minerva Campbell - Pacifist!Chara
 * Mr. Pig -
 * Neptr
 * Peppermint Butler
 * Prismo
 * Ricardio
 * Root Beer Guy
 * Shelby
 * Starchy
 * Susan Strong
 * Tree Trunks -
 * T.V.
 * Viola

Gender-Swapped

 * Fionna
 * Cake
 * Marshall Lee
 * Lord Monochromicorn
 * Ice Queen
 * Fire Prince
 * Prince Gumball
 * Lumpy Space Prince