The Masquerade is related to the seasonal world event Hallow's End. Completing this achievement is criteria for the meta achievement . Note that the does not count towards this achievement.
Hallowed Wands are given out during the Hallow's End festival in Azeroth and Outland. They are one of the random drops from . A Handful of Treats can be obtained by looting the Candy Buckets during the or in a after freeing a town from the Shade of the Horseman.