Answer:
I can move even when you are still. I can be one or many.
Although my cow is dead, I still beat herΒ What a racket she makes.
My first master has four legs, my second master has two. My first I serve in life, my second I serve in death. Tough I am, yet soft beside. Against ladies cheeks I often reside.
What do you throw out to use and take in when you're done?
Look into my face and I'm everybody. Scratch my back and I'm nobody.
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.