Dee Dee comes from Five Nights at Freddy's: Ultimate Custom Night, the 2018 custom-night game that lets players build their own roster of animatronics. In the game she makes brief, unexpected appearances in the office and can add another character to the night, which is why FNAF players associate her with sudden changes and rising difficulty. Clips of her arrival spread through gameplay videos, edits and soundboards, and the sound remains popular because it instantly signals a twist for anyone who recognises the game.