Yes, the leaves are turning brown and the pumpkins are getting cracked out as we welcome this season of spooks, and Hearthstone's getting in on the action too. Or rather, Hearthstone's Fireside Gatherings.
This basically means that if you participate in any established Fireside Gathering Tavern (local events) on or after October 17th you'll be able to get your hands on the alternate teeny hero, the Warlock Nemsy Necrofizzle.
"This pint-sized Warlock will creep her way into your Hearthstone collection if you play any Fireside Brawl at a Fireside Gathering Tavern. Even though it’s Hallow’s End, have no fear—Nemsy will continue to be available at Taverns even after this spooky celebration meets its . . . end," it says on the official blog post.
You can also host your own your own event by whipping up your own Tavern. You can find all of the details on how to do that in the post linked above. If you want a chance to get Nemsy, however, you'll have to establish your Tavern. "A Tavern becomes established after you’ve hosted a Fireside Gathering that had at least three unique patrons in attendance."
Keep in mind, this month's Brawl is Tag Team, so you'll need to find a pal. Find a Fireside Gathering right here.