Nightmare Balloon Boy is a major antagonist and one of the nightmare animatronics of the Five Nights at Freddy's series, first appearing in the Halloween Update expansion (both Standard and Halloween Edition) for Five Nights at Freddy's 4, where he is featured in his minigame known as "Fun with Balloon Boy" and functions very similar to Plushtrap. It is confirmed that he has an impact on the lore; whether his role is important or not is still yet to be determined.