In Celtic legend, the figure known for the myth of the Green Knight is Sir Gawain, a knight of King Arthur's Round Table. The Green Knight challenges Gawain to a test of courage and honor. This tale explores themes of chivalry, temptation, and the search for authenticity, as Gawain navigates his quest while grappling with his own moral values. The Green Knight serves as a representation of nature and the mystical, embodying the complexities of human growth through trials.