Silent Hill Siren

Origin
Civil defense sirens are mounted in fixed locations and used to warn of natural disasters or attacks and sometimes to indicate when the danger has passed.

Silent Hill is a Japanese survival horror video game franchise created by Keiichiro Toyama. It is set in the series' eponymous fictitious American Town, Silent Hill. Each game follows the blight of an "everyman" who arrives in the town trying to overcome an issue in their past. The first three games centralize around the Mason family of Harry and his adopted daughter Cheryl, along with widower James Sunderland as they uncover their sins which the town amplifies. A warning to those within the town limits when the darkness is coming an air raid siren is often heard before the warping of the world by darkness, fog and ash.

Effects
Must be kept under a light, if exposed to darkness will wail and spew out thick fog, creatures come out of the fog.

Collection
The only documented creature was a pack of dogs that resemble pit bull terriers with black fur and upside-down heads.