Xirix'iarus

Once a common myth and genuine danger in the seas, Sirens were a menace during the Golden Age of Piracy.

Xirix'iarus was a siren like many others in the sense that it roamed the high traffic oceans of the Caribbean and hunted for sailers both for food and for pleasure.
However Xirix'iarus was different from other sirens as it often hunted for humans much closer to their habitats. While most sirens stuck to protecting certain landmarks, ship wrecks and island in the Carribbean, this one would sometimes transform into a human and roam the docks, sea towns and plantations to hunt also.
It's home was a series of ship wrecks shoved between two peaking rocks known to sailours and pirates alike as the "Twin Knives" due to the way the rocks would cut through a ships hull so easily.

When the sirens would wait at the Twin Knives to hunt, they would turn into any number of forms to match the wishes of the prey and sing to the pirates until they would fall into the water (where they would drown before being consumed).
If the men proved to be strong of will and unwilling to look over the edge of the boat, the sirens would then climb the ship themselves and drag them overboard to kill.
There is a common misconception that sirens only effect men, but it was proven false on multiple accounts. When a woman was onboard (albiet rarely and often as slaves or prisoners), sirens would have no trouble transforming to their needs too.

Xirix'iarus was no different in that manner, but was also said to have a few 'favourite' forms it would transform into the most.
♦ An elderly woman that roamed the streets and docks. She would state that her husband was killed while fishing but left a fortune for her alone when spoken to and often lured muggers into dark alley ways to kill them in this form.
♦ A young 'stowaway' boy eager to work on a ship as hard labour. Using this, it would get hired or kidnapped for hard labour on pirate ships where the siren would then kill each member one by one, sometimes throwing bodies off the edge of the boat to feed other sirens and marine life.
♦ A middle aged Jamacian man to be handed over to wealthy white men and sold into slavery and work on fields and plantations. Interestingly enough, the siren would only kill the owners and slavers of these plantations while in this form while freeing the workers.

It was unknown if the creature chose these forms simply as personal preference or because it has an advantage over how it could lure people to their deaths.

Xirix'iarus died at the age of 347 when it was cornered while still in the old woman form. Too far from water and surrounded by the angry families of those it has killed, the siren perished to pitch fork stabs, burns and clubbing. The creature was sturdy and survived longer than expected until was chopped into several smaller pieces, cooked and eaten.
It is said that the flesh of the siren poisoned those who ate it, killing more humans even after death.