i would say no to that, below is list of ONLY place you will get pumpkins, and refills from certain adventures (list of adventures was on test server, but i didnt see it there)
Unlocking Halloween 2016 Achievements
Sending Explorers on a Treasure search
Collecting pumpkins that spawn on your home island (guaranteed each spawn, 1 Pumpkin per collectible)
Winning rewards for defeating Golems
Completing Halloween quests
Producing them with Pumpkin Cemeteries
Trading with other players
Item gifts from friends
Buying pumpkin packages in the Shop
TIP: i suggest all players check their profile on homepage, and make sure the newsletter is ticked, as they normally send out a few pumpkins and event resources during the event
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