Siremones Concept Picture
I don't know, man. I was trying to come up with something for Sirens that was more creepy and different from the myth of Sirens being beautiful bird ladies. I thought it would be cool if they were something ugly like these things but still sang beautifully to give adventurers the wrong impression. There's probably something cooler that could have been done.
Elemental weaknesses: Fire and Sand. Sirens are weak to most of Fire's subtypes, but are less susceptible to Acid and Light.