Would you mind if I helped with the beast list?

If so, would I be able to include sub-class beasts that don't have to attack necessarily, but help at times? 
I just find this really cool. 

As for the first image you liked Macabre, I immediately thought of an almost mermaid like tale for them. They lure strong men in with their voices, singing at tunes that would hypnotize them, though would not affect women. The trance-like spell would hide their true appearance to the men, letting the men invision whomever they want. Only when they go in for the kill, stopping their songs would the men break from the vice-like trance. By then, it would be too late. 
I think that these witch-like beings would definitely live in dark forest, or near swampy areas. As for their name, it would have to be majestic, yet powerful. A mirror to them.