In my opinion, I think he is the one that gave life to the animatronics. I believe in the theory that is about the night-guard being the one whom killed the five children then stuffed them in the animatronics. The marionette is the one whom gave them life again. (What I believe he is)
Crying child and mom.He/She have both genders. In FNAF 2 song,mother kills herself.Become a puppet! In minigame.Purple Guy kills crying child.And,Marionette/Puppet jumpscares come here!It means that crying child is Marionette and mom is,too.It's my opinion.