The Green Man who accompanies the dancers throughout Spring, Summer and Autumn is found in various forms in many culture around the world. In the British Isles representations of the Green Man are found in Churches and on monuments dating back to the 2nd Century. He is, of course, widely celebrated in many pub names. He is very much the symbol of The May, the traditional beginning of spring and the regeneration of the life cycle.
Many medieval Christian churches in Britain contain a significant number of carvings, either in wood or stone, representing the figure known as the Green Man. These generally take the form of foliate heads and faces with leaves sprouting from the eyes, lips and ears, so that the face seems to be peering from amid the foliage, or to be actually made of leaves. It would appear that this is example of the early Christian Church utilising older pagan symbols.
If you wish to learn more of the mythology of the Green Man two excellent sources are given below.