WoWDB

To get this achievement, you must obtain the following:

The Sinister Squashling pet and the Hallowed Helm, both of which:

• Can be contained in the Loot-Filled Pumpkin that drops once a day from the Headless Horseman.
• Can be contained in the Crudely Wrapped Gift which you obtain after the Stop the Fires quest.
• Can be bought from Dorothy (Alliance) and Chub (Horde) for 150 Tricky Treats each.