It is similar to the Air Screamer, although its head has been replaced with a solid mass of worms, and its body is more humanoid in shape. The aerial beast is also darker and faster.
It behaves much like the Air Screamer, but is much more vicious and relentless than its Fog World counterpart. It can take a fair amount of damage before going down. The main danger of the Night Flutter is its versatility and ability to move much faster than Harry Mason can. Fighting one can be difficult, as several ground monsters will also pursue Harry while combating the Night Flutter. The best thing to do when this occurs is flee. It is nearly impossible to kill it with a melee weapon, so firearms are advised, the shotgun particularly. If enough ammunition is available, the handgun will work just as well, but will take longer to defeat.
The Night Flutter's worm head may symbolize Alessa Gillespie's disgust for worms and the like. The worms could also symbolize change, particularly the change that the Otherworld brings, or deterioration similar to how ants symbolize deterioration in artwork by Salvador Dalí.
The Night Flutter could also prove symbolic of Harry's belief he may be losing grasp on his sanity, and could also stand for the overall decomposition of all things he had originally known as orthodox. Worms are common decomposers, and seeing a mass of the creatures completing shrouding sight of the creature's head could be a metaphor for one's sanity being eaten away.
It is also noteworthy that the Night Flutter, compared to its Fog World counterpart, looks more similar to Incubus, especially in skin tone and wing anatomy.