The Mari Lwyd is a wassailing folk custom found in South Wales. The tradition entails the use of an eponymous hobby horse which is made from a horse's skull mounted on a pole and carried by an individual hidden under a sackcloth. It represents a regional variation of a "hooded animal" tradition that appears in various forms throughout Britain.

The custom was first recorded in 1800, with subsequent accounts of it being produced into the early twentieth century. According to these, the Mari Lwyd was a tradition performed at Christmas time by groups of men. They would form into teams to accompany the horse on its travels around the local area, and although the makeup of such groups varied, they typically included an individual to carry the horse, a leader, and individuals dressed as stock characters such as Punch and Judy. The team would carry the Mari Lwyd to local houses, where they would request entry through the medium of song. The householders would be expected to deny them entry, again through song, and the two sides would continue their responses to one another in this manner. If the householders eventually relented, then the team would be permitted entry and given food and drink.

Dans le texte ils ne disent pas vraiment ce qu'est censé être la représentation de ce cheval (peut-être dans la vidéo, mais comme jy trave que dèche à l'anglais ... )