The T-mas card tradition began with "Peace" in 2006 and "Believe" in 2008, and since 2011 I've tasked myself with creating a new design every year (see the latest design and all currently available cards here).
But the tradition of T-mas itself goes back further, to my sister, who decided we needed a holiday to celebrate America's only true folk hero. T-mas activities include the writing of Pity Lists, the construction of wooden "fools" from sticks which are tossed onto an open fire, and of course a hearty meal including lots of nutritious vegetables and milk. Though usually held in winter, T-mas can be celebrated any day. But remember, if you disrespect anyone's mother, T-mas is cancelled and you have to wait another year!