A-90 comes from DOORS, a Roblox horror game created by LSPLASH. The entity was introduced with the Hotel+ update in 2023 and appears in The Rooms, an optional area inspired by another Roblox experience called Rooms. When A-90 appears, players must immediately stop moving to avoid its attack. Its warning cue became recognizable through gameplay videos, challenge runs, and reaction clips. Creators still use it because the abrupt signal communicates danger and forced stillness even outside the game’s original setting.