I love the Santa hats, but I think it would be a funny addition if there were an anti Santa hat called the Bah Humbug. It could just be the same thing in black.
Maybe they would magically turn into Santa hats on 12/25 to keep with the Christmas spirit.
Browniebear
Put up trees around Haven, and have them ignite on the 25th December to "re-ignite" the sun. You know, one of the original "Christmas" traditions before the Christians stole it.