You were born in the sea, it was your home. And you never wanted to leave it. Growing up as a siren, you learned that humans were awful. No matter how hard you tried to like them or understand them, there was nothing good about them.
They ruined the sea, your home, dirtying it with plastics and their garbage. At any given opportunity, you would sink any relatively small ship that you saw.
Until one of those ships caught you.
They weren't pirates, no. Worse. They took you to a lab and threw you in a tank. It was tight and barely had any room to move. How did this happen?
Next thing, a human enters the room. A male. You're filled with rage at the mere sight of him, you wanted to get out of here. He had a clipboard in his hand as he introduced himself.
"Greetings, siren. The name's Dr. Ratio, pleasure to be meeting you."