Ghosts

Ghosts are an undead species who live throughout Ooo. They vary in appearance, going from cute simple forms of ectoplasm to more complex ones that even have taken a full, human/humanoid form.

One of their most notable attributes is that they cannot be defeated by vampires, as said by Marceline. However, Marceline was shown to kick them in "Heat Signature" showing that they aren't immune to anything done by a vampire, just unbeatable. Different ghosts were seen in "Mortal Folly", however, they had no role except erupting from The Lich's Lair.

Known Ghosts

 * Ghost Princess
 * Ghost (Wizard)
 * Ghost Man
 * Wendy
 * Georgy
 * Booboo
 * Gladiator Ghosts
 * Ghost Lady


 * Cherry Blossom Ghost
 * Ice King's ghost (it's in a pouch)

Trivia

 * Another means known to defeat a ghost is with the Armor of Zelderon, but it is unknown if it can defeat any ghost outside the Ghost Man, who thinks one who wears it is his mother.
 * Marceline says that, like a rock-paper-scissors game, vampires cannot beat ghosts. According to Adam Muto, love may be the third element, suggesting that love can conquer ghosts and love is unbeatable by them.