A brief monster face appears in a Forest Shack.

Scary triggered events are random encounters throughout the game where apparitions suddenly appear in some part of the map to scare the player. A famous example is the girl in the hospital level. Others are a bit more difficult to spot due to their brief existence, such as the monstrous faces that appear in random windows and shadows. Of notice is that the triggered events are generally innofensive and merely scare the player or are triggered before too much enemies are about to spawn ahead in the levels. Other examples include audio scares, such as tripping along some air vents and hear a loud clanging and moaning noise, this in particular happening in the Backalley level. Examples in this page will not include audio files due to the Wikia's limitation of sending any audio files, but video ones, which would make it all more difficult to record a simple 5 second video to merely show something anyone could experience by downloading Afraid of Monsters or Cry of Fear.
Hospital girl

An example of a triggered event using HL functions to scare players.