If you went into the second Five Nights at Freddy's game without any forward knowledge, this is probably how you first saw the puppet. Keeping a music box wound to distract the animatronics is one of the keys to survival in game two, and failing to do so results in a lunging hug from this sailing sock puppet.
Perhaps the most terrifying aspect of this scare is that once you've failed to prevent the puppet from coming for you, nothing can stop it. You can only close your eyes and pray for the new morning to save you from your inevitable kill screen.
Markiplier has a good example of the tension build up in his video below, showing the feeling of helplessness new players experienced when cornered and faced with this inevitable fate.