Every Halloween starting at 6:00 p.m., Jack will be at a random in your town. The only problem is that everyone dresses up like him! However, you'll notice which one is the real Jack simply by the fact that he won't follow you around, unlike the villagers. Make sure that you have candy before you talk to him, or else he will play a trick on you. If you give him candy, he'll give you an item from the "Spooky Series". There are 12 in total.

Spooky Bed - Give Jack a piece of candy.
Spooky Bookcase - Give Jack a piece of candy.
Spooky Carpet - Give Jack a piece of candy.
Spooky Chair - Give Jack a piece of candy.
Spooky Clock - Give Jack a piece of candy.
Spooky Dresser - Give Jack a piece of candy.
Spooky Lamp - Give Jack a piece of candy.
Spooky Sofa - Give Jack a piece of candy.
Spooky Table - Give Jack a piece of candy.
Spooky Vanity - Give Jack a piece of candy.
Spooky Wall - Give Jack a piece of candy.
Spooky Wardrobe - Give Jack a piece of candy.