Moon River (ムーンリバー, Mūnribā) is a character in Killer Is Dead. She is the apparent "Goddess of the Moon", and lives on its dark side. Mondo Zappa is hired by Moon River to execute a man named David, whom she accuses of having usurped her throne. Mondo subsequently travels to the moon to confront David in his mansion.
Moon River also appears in some of Mondo's dreams, playing with him when they were children.
- She appears to look like Audrey Hepburn role in Breakfast at Tiffany's in which she sings the song Moon River.