Here are the common monsters of Silent Hill 2.

Lying Figure

Area: On the Streets, Prison
Attacks: Spews poisonous mist and also falls to the ground and moves quite quickly.

Lying Figure

Mannequin

Area: Apartment building, Hotel
Attacks: Flails with legs?

Mannequin

Bubble Head Nurse

Area: The Streets and Hospital
Attacks:
Swings an iron pipe!

Nurse

Mandarin

Area: Labyrinth, Hotel
Attacks:
Hangs from the ceiling and reaches out to attack with tentacles.

Mandarin

Creeper

Area: Apartment Building and Prison
Attacks: Little roachlike monster that skitters around on the ground.

Creeper

Doorman

Area: Lakeside Hotel
Attacks: Tries to close the door on you, quite literally.

Doorman