From now through the end of the month, TERA players can take part in a number of spooky events to celebrate Halloween. Console players will find the Festival Hall dungeon and several different costume packages. Meanwhile PC players need to use Halloween Cannons to "repel waves of monsters intent on stealing every last bit of candy". Successful efforts will net players some of that candy to trade for mounts, pets, costumes, masks and much more.
You can check out the full list of goodies on the TERA site.