Characteristics
Overview
Open for a surprise, or collect 10 to upgrade to a medium loot bag containing better loot!
Ten pieces of Halloween candy become one of these, and from there you pick: open it for whatever surprise is inside, or keep collecting. The game's own text pushes the second option. Ten small bags upgrade into a medium loot bag with better loot.
Picture a trick-or-treat round on an October server. You run the event with a pumpkin basket, come home with pockets full of candy, and suddenly the inventory holds a small pile of bags. A stack is exactly ten, so a full slot is the moment to decide. Opening them one by one is fun for a minute. If you plan to stay all event, saving pays more, because the better loot sits in the bigger bags.
What exactly falls out is not in our data. Earlier pages on Halloween cosmetics such as the glowing eyes point to event bags as their source, so expect costumes and seasonal odds and ends rather than a raid kit.