C and P'd from other forums. I followed this and now have everything so, if you got some down time between captivating Kirin and dethroning King Behemoth...
By matthios(sp?) of Lakshmi
There are 8 different Rare/Ex items you can get from the Halloween event: Pumpkin Head, Pumpkin Head II, Horror Head, Horror Head II, Trick Staff, Trick Staff II, Treat Staff, and Treat Staff II.
Both Pumpkin Heads and both Trick Staves aren't high-quality items; both Horror Heads and both Treat Staves are HQ items. When I say "alternate," I mean whether or not the item has a II in its name--Pumpkin Head II is the alternate of Pumpkin Head, and vice-versa, for example.
1. Only give saruta oranges bought from NPCs (like in Raimbroy's Grocery in Southern Sandy). They are by far the cheapest treat to give.
2. Find NPCs within a particular zone that not many people seem to go to. Stand in front of that NPC and trade oranges over and over until you get an item. If you get an item other than a jack-o-lantern, then zone and come back in a little bit. (There is a time interval involved before you can get another item, although I am unsure of the exact time--wait 5 minutes just to be safe) If you get a jack-o-lantern, move to another NPC within that zone with not many people around it and commence trading oranges. Follow this pattern until you receive an item other than a jack-o-lantern.
3. Okay, this is where things really get important. This is absolutely key to understand if you want all the items: what item you get depends on what you have equipped. The game randomly chooses between giving you a headgear or weapon item. If you have nothing in the chosen slot, you get a random non-HQ item for that slot (so if the game chooses "headgear" and you have nothing on your head, you get either Pumpkin Head or Pumpkin Head II). The game ignores non-Halloween items in the headgear and weapon slots and counts them as if nothing was equipped there. If you have a non-HQ Halloween item in that slot, you get the HQ version of it (so if you have a Pumpkin Head on, you'll get a Horror Head). If you have a HQ version of that item, you get the non-HQ version of it.
3. If you have nothing in the chosen slot and have a non-HQ version of one of the items that goes in that slot in your inventory, you get the alternate version of that item. For example, if you have Trick Staff in your inventory but not equipped, you'll get the Trick Staff II.
So, here we go with my masterpiece:
If you want a Pumpkin Head or Pumpkin Head II: have no Halloween items equipped in headgear slot
If you want a Trick Staff or Trick Staff II: have no Halloween items equipped in weapon slot
If you want a Horror Head: have Pumpkin Head equipped in headgear slot
If you want a Horror Head II: have Pumpkin Head II equipped in headgear slot
If you want a Treat Staff: have Trick Staff equipped in weapon slot
If you want a Treat Staff II: have Trick Staff II equipped in weapon slot
So, as an example, this would be an appropriate order of getting the items:
Pumpkin Head (Equip it) > Trick staff II (Equip it) > Treat staff II (Equip it) > Horror head (unequip both Pumpkin Head and Treat Staff II) > Pumpkin head II (Equip it) > Trick staff (Equip it) and so on...
Basically, the idea is to remove the possibility of receiving any other item than the one you want. For example, the last item I had left to get was Horror Head. Thus, to get it, I had to have Pumpkin Head equipped in headgear slot and Treat Staff II equipped in the weapon slot before the NPC would give it to me (because otherwise with no HQ Halloween item in weapon slot, the NPC would try to give me a Trick Staff II).
I dream of oranges now... Happy Hunting!