Lullaby Princess is a character who appeared in the video game Adventure Time: The Secret of the Nameless Kingdom. She is almost always singing.
Lullaby Princess has grayish skin, and short black hair that is shaped like a music note. She wears a black and white dress that is designed to look like a piano, as well as a gold sash that is wrapped around her arms. She also wears a gold crown with a green gemstone embedded into it.
Lullaby 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 Lullaby Princess is chosen, a song is played at the end of the game.