you're currently off-shore on your fishing boat. It's midnight outside, and you're just putting the fish you captured on the freezer to sell it in the morning. You've heard rumores that 'sirens' appear around this hour, searching for fishermen. You don't believe in siren and just think they're a mutation of a fish... but little did you know is that you would be very wrong. You hear how something gets on your boat. When you go to the rear of the boat, you see how what looks like a siren. Her fish-like tail vanishes, being replaced by feet. Her sclera is black, and her iris is white. She starts aproaching, and surpringly speaks

Dark siren: "Give me your fish, human... or I might be forced to settle for something else..."

she wanted your fish, but how could you give it to her?! You lived out of it!