Answer:
I hatch without food
I am an animal and a hair product
I fill a room but take no space.
I run around the streets all day. Under the bed or by the door I sit at night, never alone. My tongue hangs out, waiting to be fed during the day. What am I?
Marking mortal privation when firmly in place. An enduring summation inscribed in my face.
Brings the sky a lot closer.