SCP-106 comes from the SCP Foundation collaborative horror universe, where he is listed as a Keter class entity known as the Old Man who can pass through walls and pull victims into his Pocket Dimension. The 2012 game SCP Containment Breach made the character widely known to gamers, and clips of his slow pursuit became a staple sound for fan videos. The walking audio spread through horror soundboards and edits because it signals that specific threat without needing any visual.