Slumber Princess is a character who appeared in the video game Adventure Time: The Secret of the Nameless Kingdom. She acts like a stereotypical hippie, acting in a calm, yet spaced out manner.
Slumber Princess has grayish skin and fluffy, light-blue hair. She wears a blue dress that has a cloud-like design on her chest and a dreamcatcher tied around her waist. She also wears a gold crown with a blue gemstone embedded into it, as well as a sleep mask that appears to function as her actual eyes, according to some sprites.
Slumber Princess is one of the three candidate princesses to rule the Nameless Kingdom. However, she and her sisters (the other two princesses) mysteriously disappear, causing Pillowmint Butler to send Finn and Jake to retrieve them so a ruler can be chosen. At the end of the game, Finn chooses one of them to be the ruler of the kingdom. If Slumber Princess is chosen, then the events of the game are revealed to be a dream that BMO had.