The Green Man is a legendary Ghille dhu.
Overview[]

ghille dhu, perhaps the Green Man, guards a cave filled with fae treasures, somewhere in the North Country of Britain. But woe unto him who tries to gain them for himself. This guardian, as old as the Earth itself, gains power from the progression of time and the seasons. He is as strong as a mountain, and is more cunning than the eldest sidhe lord. He does not die and get reborn as the rest of the ghille dhu, but is their lord, the soil from which they spring. He is mysterious and secretive, but when he appears, he is like the crack of thunder and the rending of earth, and no one who has seen him has emerged unchanged. That's neither here nor there, though, for no one has seen him for centuries. With many of his followers, he has retreated into The Vale, something like a huge, majestic freehold to the ghille dhu, and (I hear) mourns the loss of the primeval forests across Great Britain.
References[]
- CTD. Isle of the Mighty, p. 13.