Place it early in a horror edit to introduce the character before any scare, then follow it with the FNAF Jumpscare Scream for the reveal and the Fears To Fathom Notification for a tense alert between scenes.
About this sound
This 4.5-second clip is Katrina's horror-mode theme from Party Club, a slow music-box melody with thin, slightly off-key notes and long pauses between phrases. It feels sad, lonely and quietly unsettling, like a childhood tune left playing in an empty room, with no loud scare to break the mood. The fan-created character comes from a community take on the music-making style popularised by Incredibox.