Embryo Princess

Embryo Princess is a princess who appears briefly in "What is Life?" and "Loyalty to the King." Apparently she has some sort of telekinetic power that enables her to create a bubble around her that resembles an amniotic sac. Although she has not talked in the series, she is not mute. Natasha Allegri came up with the idea for Embryo Princess.

Appearance
Embryo Princess looks like a human fetus. She has a golden tiara with a magenta stone in it, similar to that of Princess Bubblegum, Slime Princess, and Princess Princess Princess's monster head's tiara. She doesn't seem to have any clothes on, and her veins are visible through her skin. Since she was originally aborted, she has Xs over her eyes in earlier designs.

Trivia

 * Her phone resembles a small pink cube.
 * According to Pendleton Ward if Finn were to marry any princess he'd marry Embryo Princess, though this was most likely a joke.
 * Her tiara resembles Princess Bubblegum's, which has the ability to block the telepathic power of The Lich.