Sirens are a mythological creature, originally from Greek Mythology. The Greek Myth variety is a little different from the standard conception.
I’ll write very minimally right now because I don’t feel like writing more. The modern day conception is basically a mermaid, but the Ancient Greeks instead thought of them as half-bird half-woman. Though the mermaid depiction is older than most people assume…I think it also dates back to the Ancient Greek times? But I don’t know whether they were contemporary or not.
That means they kinda vaguely lined up with harpies…but let’s not get into that either.