Throughout the story we find out that Bertilak de Hautdesert  is disguised as the Green Knight through the mystical powers of Morgan le Fay. One characteristic of Bertilak/Green Knight is his commitment and seriousness towards verbal contracts with Gawain. As the Green Knight, after he picks his head up off the ground after being stuck by Gawain he reminds Gawain of their meeting in one years time. Then as Bertilak he makes an agreement with Gawain about sharing what they obtain throughout the day.

The Green Knight - http://littlefrog626.deviantart.com/art/The-Green-Knight-155764806

The role of the Green Knight has been portrayed throughout many different medians, from tall tales to movies. His most common role has been that of the devil. Like the devil in many works he is this mysterious, deceptive, supernatural being. Trying to make fault out of its victims. His actions are laid out to trick people into difficult situations.

Beauregard, David N. "Moral Theology In Sir Gawain And The             Green Knight: The Pentangle, The Green Knight, And The                 Perfection Of Virtue." Renascence 65.3 (2013): 145-162.                 Academic Search Complete. Web. 3 Dec. 2013.

Ridland, John. "Sir Gawain And The Green Knight." Hudson Review     62.4 (2010): 549-562. Literary Reference Center. Web. 3 Dec.         2013.

RUDD, GILLIAN1. "'The Wilderness Of Wirral' In Sir Gawain And         The Green Knight." Arthuriana 23.1 (2013): 52-65. Humanities         Full Text (H.W. Wilson). Web. 3 Dec. 2013.

Swanson, Catherine. "Sir Gawain And The Green Knight."                     Masterplots, Fourth Edition (2010): 1-4. Literary Reference             Center. Web. 3 Dec. 2013.

TWOMEY, MICHAEL W. "Sir Gawain And The Green Knight."             Arthuriana 23.3 (2013): 106-108. Literary Reference Center.             Web. 3 Dec. 2013.

Obviously the Green Knight is green. Many  people associate green with nature, life, money and the balance of well being of others. In this case the dark green represents jealousy, ambition and greed. Which is interesting because the Green Knights opponent, Gawain does tend to exhibit both greed and ambition. Greed is when he refuses to give Bertilak the green girdle he obtain from the lady of the house and then his ambition to use it as his trump card against the Green Knight.

I based my blog on the story "Sir Gawain and the Green Knight" It's about a challenge between  Gawain and the Green Knight. Its interesting because you want to find out how Gawain reacts to his opponent, when the knights picks up his head and reminds Gawain of their meeting. Its funny how in the end Gawain didn't think he handled it well but in reality he did what every thought was the right thing.

The Green Knight is this story is quite different compare to other antagonist in other stories. He has a calm gentle like presence, yet he is also dark, mysterious and cunningly dangerous.
With a character like that, who wouldn't want to know his angle.