Erdudfyl daughter of Tryffin is the eleventh name in the list of maidens at the end of the long list of Arthur’s men in Culhwch and Olwen.
It is usually assumed that Edudfyl’s father Tryffin is the same Tryffin listed as father of Drudwas and that Erdudfyl is the same unnamed woman that appears as the sister of Drudwas and mistress of Arthur in the story of the Death of Drudwas.
See Drudwas for further information.