I have never laid eyes on a live opossum in my life (outside a zoo). And I certainly didn't expect the first one I saw to be on a railing just outside the door of a house on Clinton Street.
This lone beast, of medium size, grey coat, pink tail and blazing black eyes, sat balanced on a wrought-iron fence just inches near the front door of Carroll Gardens home, around 9 PM on a Sunday night. He/she was quite alone (opossums are typically solitary), and looked rather scared (though the animal did not move an inch as several people on the sidewalk stopped and stared). Why the thing would want to hover under a bright door light where everyone could see it, I don't know.
A more interesting question is how it ever got in such a densely populated section of Brooklyn. It is apparently not an unusual occurance. There have been recent stories of opossums in Park Slope and Dyker Heights.