In-game Shop: Accessories -> Hats & Headgear
Price: 20 Veteran Points, account wide per gender.
This top hat is similar to the Item-of-the-Month Frosty tentacle topper and the reward Tentacle top hat.
This item was not displaying properly and is gone from the store at the moment. Hopefully it’s getting fixed! For now, the women’s version works. It’s working!