The Mari Lwyd is a Welsh folk tradition that is also called "Y Fari Lwyd" in Welsh, and it involves using a horse's skull to make a school mascot or toy out of it. People from Wales celebrate this tradition at different times throughout the year, but mostly during Christmas or New Year's Eve.
To make the Mari Lwyd, people would typically take a horse's skull, clean it, and then decorate it with ribbons, bells, and other shiny items. They would then attach the skull to a stick or pole and place a white sheet over it, so it looks like a horse head with a ghostly appearance. Once the Mari Lwyd is ready, groups of people would then take it to various houses and pubs to sing traditional songs and dance with it.
The idea behind the Mari Lwyd tradition is to bring good luck and happiness to the community for the upcoming year. It is also believed that the Mari Lwyd is a way to honor the ancient pagan gods of the Welsh mythology, which were rooted in nature and animals.
Overall, the Mari Lwyd is a fun and unique tradition that involves creativity, storytelling, and community bonding. It may seem a bit strange or spooky to some, but it is an essential part of Welsh culture and heritage.