You hear the moaning first. A dull, primal tone which sends a prickle skittering over your skin. Next comes the rattling, as the nearby drain grate is pushed and pulled ferociously by grey, decaying hands. The stress is too much for the rusting metal and it bursts open, a shambling husk of a corpse dragging its way up and halfway onto the street. There is no aggression in its lifeless eyes as it stares at you, just a desire to feast on your warm blood.