The Mask Task

The Mask Task is related to the seasonal world event Hallow's End. If you destroy the mask you have received, the criteria stay completed. Note that masks are BoP and cannot be traded.

Locations
Flimsy Masks can be found within Treat Bag from Trick or Treating with innkeepers during Hallow's End. You have about a 50% chance to get a Treat versus a Trick (typically a costume), and a 25% chance that your Treat Bag will contain some mask.