Stack Exchange invites you to celebrate the end of a great year …with HATS! As you use your site, you'll discover hats and other items hidden behind certain actions. Collect all of them, some of them, or none of them, but be quick – the hats get put back in their boxes on January 4th!

A New Hope

post or vote on Dec 18

Thalia

reopen or undelete

Sufganiyot

post or vote on Dec 14

Timey Wimey

edit 5 old questions

The Airing of Grievances

post/vote on meta on Dec 23

Greeter

edit & upvote a first post

Melpomene

close or delete

Wireless

vote 10 times via app

O Tannenbaum

post or vote on Dec 25

Vote Early, Vote Often

250 votes on 7 consecutive days

Do it Yourself

answer own question, both +3

Cerro de Potosi

earn a silver badge

Specialist Hatsman

collect 11 hats

Every! Body! Gets! A Hat!

help find 20 unique hats

Do You Even Lift?

five +5 answers

El Dorado

earn a gold badge

Hat Trick

rep cap 3 times

Auld Lang Syne

starred chat, ±12h from Jan 1, 0:00 UTC

Fan-hat-ic

visit on 10 consecutive days

Speedy Delivery

answer in 30 min, +3 and accepted

Carl Fredricksen

receive only upvotes (≥5) in a day

Field Work

nice question asked via app

Weed Eater

accepted answer to Tumbleweed

Researcher

search on 3 consecutive days

Explorer

first post, +3, 3 days old

Copernicus

answer +3 a question with accepted answer

Living in the Future

self-answer +5 an old question

I’m Batman

edit question closed by others, gets reopened