Trick or Treat
During Halloween 2006 & 2007 you could say "trick or treat" and a target cursor would appear. Once you have the cursor up target any NPC and they would give you one of several items or trick you with a nasty surprise.
Treats included food that said "9th Anniversary (Food Name)" on it, Candy such as caramel apples, rock candy, and licorice, and even rare items like the Jawbreaker Gum.
Tricks included making your character bleed all over, blowing your character up (leaving body parts all over) changing your character into another form such as a spider.
Other Notes:
You could only trick or treat the same NPC once every couple of minutes. I ran around cove and started at one end and worked my way down hitting every NPC along the way then I would go back to the first and be able to hit that one again and start my circle over again.