SCP-173 began as the first SCP Foundation entry, posted online in 2007 and built around a concrete statue that attacks when not watched. The character spread far beyond the wiki through the 2012 horror game SCP - Containment Breach, YouTube playthroughs and fan animations, where its movement is usually paired with scraping stone sounds. This rattle version became a shorthand on soundboards for that specific threat. It remains popular because viewers who know the lore understand the danger instantly, even without seeing the creature itself.