Stalker

Description:
They are basically the ghostly form of Grey Children: small, child-like, knife-wielding monsters, the sole difference being that Stalkers are "invisible" (vaguely delineated, and as such, hard to see) and their presence is not detected by the radio. They appear to be the matured form of the Larval Stalker, which is just as ghostly and silent, albeit passive in behavior, and otherwise harmless.
Method of Attack:
These little monstrosities attack with knives and they're damned hard to locate. So they can appear from several angles at once and in small groups of three to four.
Symbolism:
None.
Reasons for Manifestation:
None.
Area:
• Sewers of Silent Hill
• Lakeside Amusement Park
• Nowhere
~Taken originally from the Silent Hill Wiki

Description:
They are basically the ghostly form of Grey Children: small, child-like, knife-wielding monsters, the sole difference being that Stalkers are "invisible" (vaguely delineated, and as such, hard to see) and their presence is not detected by the radio. They appear to be the matured form of the Larval Stalker, which is just as ghostly and silent, albeit passive in behavior, and otherwise harmless.
Method of Attack:
These little monstrosities attack with knives and they're damned hard to locate. So they can appear from several angles at once and in small groups of three to four.
Symbolism:
None.
Reasons for Manifestation:
None.
Area:
• Sewers of Silent Hill
• Lakeside Amusement Park
• Nowhere
~Taken originally from the Silent Hill Wiki