The Galactic Moon Festival was an event celebrated at Mos Eisley and Moenia during the Galactic Civil War.
Moenia during the Galactic Moon Festival
The Galactic Moon Festival was created by Jabba the Hutt to gain more support from Tatooine and Naboo. He grew tired of festivals of love and life, so he aimed to create the scariest event of the year. He sent Aponte to advertise the event, while Z'ozpheratu was tasked with handing out costume holo-projectors in both cities.
These holo-projectors would allow spacers to "dress up" in a number of scary costumes, including Droidekas, Toydarians, and Hutts. These celebrants would attempt to scare others with their costumes, by exclaiming, "Trick or treat!" If they were genuinely scared or impressed by the costume, the participants would be given Galactic Moon Coins. These coins could be given to Z'ozpheratu in exchange for certain prizes.
This Galactic Moon Festival was first introduced to Star Wars Galaxies with the "Game Update 5.10," published on October 14, 2008, in order to coincide with the real-world festival of Halloween. The festival also shared similarities with Halloween.