The seductive yet murderous Siren is the guardian of Lake Nostos, luring in all who come to the lake to pull them to their watery graves. Prince David once ventured to Lake Nostos in search of the magical water that could reverse the Golden Touch that turned Frederick into a statue, and faced the Siren, who eventually took the form of Snow White in an attempt to mesmerize David. However, when David saw through the illusion, the Siren dragged him underwater until David stabbed and killed her. Upon her death, Lake Nostos eventually dries up, leaving behind her corpse.
- The Siren is based on sirens in general, from Greek Mythology.
- S1, E13: "What Happened to Frederick" (flashback)
- S2, E03: "Lady of the Lake" (corpse)