Siren is a female ghost which is covered by clothes-like energy. It could create its copies and misguide its enemies. It changes colors as you damage it.
First form: Purple hair, pink skin and green robes. Second form: Lighter Blue hair, pink skin and yellow robes. Final form: Darker blue hair, lavender skin, and brown robes.
Like all sub-bosses Siren can be captured in a trap.