Hallow's End 2012 begins on Thursday, Oct. 18 and runs through Wednesday, Oct. 31 this year. As with most of the game's holidays, Hallow's End is required for the yearlong meta What A Long, Strange Trip It's Been that grants the Violet Proto-Drake. Completing the required Hallow's End achievements will also award the title the Hallowed.
Last year, Blizzard added some major updates and improvements to the holiday, one of which completely eliminated the hassle behind one of WoW's most hideous RNG nightmares, and one of which left us with two very badass non-combat pets. In essence, Tricky Treats -- once a vomit-inducing item that dropped in spades from the holiday boss, the Headless Horseman -- are now a form of currency that players can use to buy pets, masks, wands, and other holiday items. 2011 also introduced a new set of quests associated with Hallow's End, one of which sends you into an enemy city without the fear of ugly death.
Bottom line: If you weren't around for last year's holiday, a lot of stuff may interest you this year. If you were around for last year, you'll still be interested, as the Headless Horseman's set of dropped epics are a lot more compelling at the beginning of an expansion. Hardcore achievement hunters will also be pleased to note an additional 10 points in the form of Tricks and Treats of Pandaria.
As with most of our holiday guides, I've arranged the achievements in the rough order they should be completed, noting which achievements are required for the meta and which aren't.