Place it at the peak of a horror edit, after a slow build, then follow it with the FNAF Jumpscare Scream before cutting to a reaction shot or a title card.
About this sound
This is a short jumpscare sound effect lasting about 2.5 seconds, centred on a sudden mouth scare. It feels startling and tense, delivering a quick shock that makes listeners flinch before they have time to react. The shock lands fast and leaves no time to settle, which is why it catches listeners off guard.