What is The Rotted-Bird?

The Rotted-Bird is a entity that looks like a giant humanoid bird with the grotesque looking of a living-corpse, his "sing" is very strange...sometimes it sounds like a bird or other animals, only that always something sounds wrong....like mixed failed imitations...

(Btw, this is a Reskin of The Woodland Stalker/Bread Dweller do not play with this two mods along)