A-90 comes from DOORS, the Roblox horror game released by LSPLASH in 2022, and appears in its hidden Rooms area reached past door A-001. The entity warns players to stop moving, then jumpscares anyone who ignores it, which turned its loud attack into a recognisable cue among fans. Clips of failed Rooms runs spread through Roblox edits, YouTube Shorts and TikTok, where the sound escaped the game as a general horror sting. It remains popular because players instantly read it as a punishment for moving at the wrong moment.