The Puppet is an animatronic who saves people like saving the kiddins when they are killed by Purple Guy. Was killed by Dave and was an important character in Old Sport's life.
Also, if you fail to wind the music box, it will either:
A: If you are not in the suit, rip off your testicles.
B: If you are in the suit, uses THE TICKLE FINGERS to trigger the springlocks and kill you.
The only thing that is known about The Puppet is that it only saves someone when someone tells him what is happening.
The Puppet is the smartest animatronic. It sometimes chooses the wrong evil then other people will think that they are evil.
In the games
The Marionette doesn't physcially appear, but appears in the Happiest Day arcade games, as the 8-Bit Puppet, who tells Old Sport what to do in order to help the dead kids get their happiest day.
It is given a bigger role, where if you fail to wind the music box, he will kill you. He will also kill you if you wear Dave's suit.
In the Premature Ending, you can talk to the music box, and the Puppet will appear and kill Dave in order to save the kiddins
If you choose Dave's path, then Dave will put locks on the music box, preventing The Puppet from leaving the box
In the Marion ending, The Puppet will call Old Sport a monster for killing the children, and will reveal that Dave killed him. He will also say he used to be a happy animatronic, but the tears it got from death were permanent. It will then make Old Sport smile, and bite his head off.
If you go the Puppet's route, he will tell Old Sport to buy a wrench to open the Happiest Day arcade game, and will tell about Dave's history, and tell how to free the kids. After Fredbear tells Old Sport to go to the Happiest Day, The Puppet will meet him, talk to him, and introduce him to the ghosts of the children. It then passes on to the afterlife.