I first learned of the 'Mari Lwyd' through Anne Pilling's The Beggar's Curse, where it is introduced as 'Old Hob'. This curious Welsh practice is not only the preferred manner of ringing in the new year there, it is also the origin of the Hobby Horse; a staple of the children's playroom.
During New Years Eve, the Mari Lwyd is escorted around the village houses, where it recites begging rhymes in a manner similar to Halloween trick or treating:
Old Hob, Old Hob, give him a tanner, give him a bob!
We hope your new year will be as strange and wonderful as this old Welsh tradition! Happy New Years!