How to get
First available during the Halloween event 2015 (Oct 20th - Nov 2nd), purchased with Candy Corn.
Available again during the Halloween event 2016 (for Pumpkins) and Halloween event 2017 (for Tricks).
It remains available at the Bazaar for those who still have social currency in stock.
Now available at Ghost Ship Cove in the first trade panel, purchased with Doubloons (rotating cycle with other Halloween decorations and chests).