The Morrlitt are a fused people; the souls of the offspring of the Morrighat herself bound into the body of a human Morrighatti. They are a new people; never before had her children gone on to live, never before had the Morrighat found herself with her children around her.
They themselves also had young, hatched out in nests around the largest of trees. Whole tribes of these Morrlitt grew up in the land around the Morrighatti settlements, and they were as one people.
When their own communal nests were ready, and when their young beginning to hatch, the Morrlitt’s own witch caste would kill the last egg to hatch and bind the soul to the stuff of the nest; enchanting it and entreating it to protect its brothers and sister. A soul bound to that place with a sole purpose. Over time these collective souls grew into each other until they could rise up with the stuff of the nests and walk amongst their kind; living sentinels of purpose. These nestlings are vile and spiteful things of hatred and single-mindedness, and are utterly devoted to the protection of their own kin.
A Nestling, again not too much of a mash-up; just a spite revenant with a bird head and added nesting material