The Puppet is a mentally-unstable animatronic from 1987. He may seem insane, but he actually knows more than he lets on. He presumably went insane due to isolation in his box as implied through the FNAF 2 reboot Let's Play. In fact he seems he knows almost as much about the history of Freddy's as Golden Freddy does. He has the ability to give life which he uses to bring life to the toilet, a toaster that created I Am Bread, and cure the hack that happens whenever animatronics play Popgoes (Albeit, since this was a theory created by themself, there is a possibility that they simply made themself the hero. Face it, we've all had those fantasies.).

They were a victim of the Fazbear Massacre and became a phantom. Thus, they fell under Springtrap's control and worked to kill the remaining Fazbear residents.
The Puppet

“I give life”