Siren Head is a horror creature created by artist Trevor Henderson, first shared online in 2018. The character became widely known through fan art, horror videos and indie game content, where its eerie siren call helped define its identity. Online, the sound is often used like a danger alarm sound effect to suggest a nearby threat before anything is shown. It remains popular because the siren is simple, instantly recognizable and easy to drop into short horror edits, analog horror clips and monster memes.