If you neglect its music box then it will break free of its prison. Once out, it can't be put back inside, and your ventilation system will drain much faster than it did before, causing blackouts and eventually a game over.
The Puppet has a white face with black, hollow eyes (aside from its jumpscare and a small in-game cutscene, in which it gains small, white pupils). Its face is similar to that of a Pierrot, with rosy red cheeks, purple stripes that stretch from the bottom of its eyes to the top of its mouth, and red lipstick painted on in an exaggerated pucker.
Its body is somewhat reminiscent of a sock monkey's, with its round, oblong shape, thin waist, three white buttons, rounded hands that feature three spindly fingers each, and white stripes on the wrists and ankles, along with a thin, long neck. It has no feet, but its legs are tapered to a point. It has neither hair nor head accessories. It's quite lanky, and according to one of the hallucinations in which it appears, it stretches from the floor to the ceiling of the pizzeria.
Behavior (FNaF 2)
Phone Guy mentions that the night guard needs to keep the Music Box wound, as the animatronics have a feature where they attempt to find sources of noise or potential customers. The source, in this case, is the Office. Keeping the Music Box wound is vital to keep the Puppet at bay; if it is left unwound for too long, the Puppet will exit the Prize Corner and will attack the night guard, ignoring the Freddy Fazbear Head, resulting in a Game Over.
The Music Box can be wound remotely by going to CAM 11. As it unwinds, a warning sign will appear next to the CAM 11 box on the camera map, as well as on the bottom right of the screen when not using the Monitor. The warning sign starts out orange, signalling that there is only one piece of the counter left before the music nears its end. It then blinks red when the timer has run out, meaning the music is about to end, and The Puppet is seconds away from beginning its attack. Once the red exclamation mark disappears, action must be taken immediately, or the player will be completely helpless against The Puppet.
It was previously thought that once the timer ran out, there was no way to stop the Puppet, but this is not true. Since the Puppet will not move while the light is on it, it is possible to hold the light on The Puppet and wind the Music Box, keeping it there as long as the Music Box is still wound. If The Puppet is caught in its first stage of exiting the box, the player still has one last chance to stop The Puppet in its tracks and prevent it from reaching the second stage. The player must still treat this as a normal Music Box rewinding, as the other animatronics can still attack the night guard.
Regardless of what happens after it begins its attack, even if the Music Box is wound up after it has left the Prize Corner, the Puppet will still make its way towards the Office, attacking in a manner very similar to Foxy. There is no way to stop it once it has begun its approach and will kill the night guard, even if they are wearing the Freddy Fazbear Head; the only way of surviving at this point is making it to 6 AM. The player will know it has left if they hear the tune "Pop! Goes the Weasel" begin to play. The player will be unable to find the Puppet on any camera once it has left the Prize Corner to attack, except in rare cases of seeing it in the Main Hall camera, as a hallucination. Depending on the night, it will take anywhere from as long as 2 minutes to as little as 6 seconds to reach the Office. This is mainly demonstrated by the Custom Night where its attack time is based on other animatronics' A.I.s.