I have done some extended research on mythical monsters, here's a few with slight descriptions: kelpie which is an underwater creature unlike the mermaid that devours others, Sirens which similar to sereias that lure sailors to unexpected fate, the body of a corvo or bird and the head of a man (normally female.)
And here is a few of my own; dark essence(s): those whom reside as an insane conscious and take the forms of humans or other creatures, dream eaters: also taking the form of a human, but a few unnaturalities. Hope this helped
how about the daughter of domo kun 15 years old brown skin color brown eyes blonde hair with laranja and blue highlights taller than acctual domo kun and her best friends are Rochelle Goyle,C.A. cupid,Spectra Vondergist,Venus McFlytrap,Rebecca Steam, and more!