Wondering if anyone has unlocked any secret hats. A beret perhaps.
You can find out how to unlock a particular hat by going to to the leader board then hover your mouse over a hat that someone has to see the requirements.
For example, hovering my mouse over the bow tie...
Or you can place the hat name in the URL, http://winterba.sh/epic-punyon-beard and it will show you more details like...
Yes, there are secret hats:
This can also be confirmed by looking at the screenshot in Hats list in profile should include each hat's name and description. The image is of Aarthi's hats list, and there are three (Cupcake, Bowtie, Propeller Beanie) which don't appear on the Winterbash main page.
Yes, there are, and we're actually keeping a list of them over on Arqade: