Alright, I wanted to wait until my Halloween stuff was released before posting it here, no spoilers for my players who browse rms ^^
The server is heRO, I can't "rate" it since well.. I made it, but I think we do a decent effort when it comes to Holiday celebrating and I think it's important to do something original for each holiday.

For the past 3 years we've had a "dark prontera" during Halloween season, it was made by one of our GM, we also change some npc for nif ones, such as the spooky kafra!
In 2007 the major cities of the kingdom were invaded by pumkingrings and autumn leaf cats, this year the pumpkingrings have received a buffing in stats/exp and rewards, and are now found in Niflheim.
Last year's quest involved a number of npc such as "Pumpkin Squire", "Pumpkin Minstrel", "Pumpkin Counselor", they all looked like halloween/dark monsters (pumkingring, jakk, bloody knight, etc.) they moved around in cities or field/dungeons, the quest was randomized so that not everyone was sent to the same npc, nor did they have the same items to gather (so you actually had to read what the npc said, those who didn't regretted it), part of the quest had you delivering food and you had a certain amount of time to do it or it would turn bad, the reward in the end was some chance items and a pair of Spiderweb Wings and a pumpkin mojo, a npc in the DB rooms was gathering mojos, once 30 players had handed in theirs it would summon the Hollow Poring, a hard MVP with sweet exp and items, similar to pori pori. This was the first quest where we introduced moving npc, which have since then been deemed as completely EVIL, and we re-used that concept in a few other quests afterwards.
This year's quest has players investigating a big mysterious creatures sighted in various cities, a scholar in Yuno hires you as his assistant, and sends you to talk to each victim to gather information. The quest sends you to most major city aside from the starting ones, and if the warp to that city is not unlocked you get it for free, if it's already unlocked you get some zeny instead. Most of the people that got attacked by the creatures did not get a good look at it, but as you interrogate them you find out that the mysterious monster is a big orange blob and that all the victims had on them something relating to pumpkin (pumpkin seed, pumpkin pie, etc.), you report back to the scholar only to find our he died! His brother gives you some of his items, as rewards for helping with his research, the player has a choice between last year's Halloween gears and 2 new ones: Witch Hat or Purple Bat Doll, they also get Exp and a wrapped mask, along with a few other small prizes obtained in the rest of the quest. The scholar's investigation got him killed before he could finish it, his spirit lingers in Niflheim, seems the creature got attracted by a concentrated pumpkin essence that he was creating, he tried to capture the monster but it fought back! He knows how to attract it now, so if the players gathers 4 pumpkin mojos they can summon the Hollow Poring! It's a toned down version from last year's Hollow Poring, a MVP doable by a small party of level 80ish players.
We'll also be having a Halloween event on friday (Oct. 31st) but can't give any spoilers on that ^_^