Halloween Costume
Overview
A costume will transform a character's appearance to resemble a costume's description creature when equipped. It does not give the character any of the creature's powers or abilities. Costumes equip to a character's Right Hand Slot and always include the Spell Channeling property.
The original five costumes were first obtained by giving Tomas O'Neerlan a red crystallized essence, which was one of three possible quest rewards by completing the Halloween 2009 Quest. Tomas stopped accepting red crystallized essences in early-November 2009.
Later with Publish 63 in December 2009, an NPC named Sarah the Exotic Goods Trader was introduced to provide a way to trade in leftover red crystallized essences or older costumes for new costume types.
Some experimentation shows that you can still be targeted by monsters while equiping the mask, and if you take damage in monster form, the costume is easily destroyed.
Original Halloween 2009 Costumes
Note: The original costumes are labeled "A creature-type Halloween Costume"
Possible costume types (from most common to rarest):