Ho ho ho, ho ho hoes; 'tis the season!
If your avatar is the same as it was last year and I gave you a Santa hat for said avatar, it's time to change it. Otherwise, you may select one of the Santa hats and/or other adornments below, and I'll use my sick graphical skillz to put it on your avatar. (If you don't choose a hat, I'll choose for you, for better or worse. [Worse.])
You know the rules, and so do I. But in case you have a poor memory, they are as follows:
Make sure your current avatar hasn't already been Santified last year or a year before that.
You can make a special request or ask for a Santa hat you found somewhere on the Interwebs, but it might be difficult to implement on your avatar. (Translation: I might be too lazy to accommodate your request.)
Some avatars won't look very good with a Santa hat, either because the Santa hat is cut off from view or for other reasons.
I probably won't be able to do animated avatars.
If you get a Santa hat from me, I'll save your original avatar somewhere and @ you after Christmas to remind you that it's time to de-Santify your avatar.
For every day beyond liturgical Christmas in which your Santa hat is still on your avatar, I will be angry and I'll probably keep @'ing you in a way that one could reasonably interpret as targeted harassment.