Here is an informative seasonal article from Wales Online:
"MARI LWYD – the Grey Mare
A horse’s skull with false ears and eyes attached, plus reins and bells, draped with a white sheet and decorated with colourful ribbons was carried around the village on a pole.
It was carried from door to door, by a party of people. At each door, poems were recited in Welsh. Those inside the house replied, also in verse, refusing to let the Mari Lwyd in until this battle of verse and insults (or “pwnco”) was won." ...(Cont.)...