Put this clip at the reveal point of the edit, after a goofy ahh sounds run-up, then follow it straight with a scream meme hit for the payoff the scene has been building toward.
Über diesen Sound
This roughly nine-second clip is a fan-style imitation of Freddy Fazbear chanting 'har har har' in a deep, robotic sing-song. It feels goofy and unsettling at once, turning a familiar horror mascot into a silly threat. It comes from Five Nights at Freddy's, the game series created by Scott Cawthon.