A Siren isn't really a sea monster but sailors have told tales of these beautiful women that sing to you and seduce you into their trap of bloodlust. They are said to eat the sailors alive or drowned them deep in the ocean.
The Banshee (or Bean Sidhe), a female spirit from Irish mythology who was said to herald the death of a member of a noble family. She was a faery-like being, associated with the Celtic Otherworld and the crow Goddess called The Morrigan.
o Morrigan banríon mór tú a bhfuil a gutha agus gothaí soothe mo phian marfach a chloisteáil mo ghlór éisteacht le séiseanna de mo anam breathe an cumhráin de mo deabhóid mo ghrá (NEW MORRIGAN, Sharon Aur, SciFi Fantasy Art-)