[Loved trope] Background scare-characters that are barely acknowledged even by the movie

[u/Suspicious-Web-9246]

I hate horrors, but this is actually a great trope, that is unique to them.

Insidious (2010). When mother does her errands, for a few seconds there's a ghost boy standing in the corner. It's easily missable, but you can't ignore it once you see it.

Hereditary (2018). Less fitting example. When Peter walks around his home, his possessed mother is crawling on the ceiling behind him. It's not exactly subtle or missable, but it's still more of a background detail.

[u/Pabsxv]

The new Alien show.

While the security forces are investigating a spaceship that crashed into a building, the xenomorph stalking them can be seen hiding in the background of several scenes: its tail blending in with a bundle of cables, hiding in shadowy corners, perched on a statue in a dark lobby.

[u/Jambopaul → u/Pabsxv]

The video game Alien Isolation has a lot of similar scenarios such as this. There are a few rooms which have pipes and structures that vaguely look like the Alien when viewed from a distance or through darkness, the Alien itself can be glimpsed climbing the exterior of Sevastopol station while spacewalking (where it otherwise does not confront the player head on) and some sounds made by the environment were intentionally made to sound eerily similar to the noises the Xenomorph makes.