Ysbaddaden Bencawr is a giant from Welsh mythology, known as the king of giants. He appears in the tales of The Mabinogion, a collection of medieval Welsh stories. Ysbaddaden is often depicted as a fearsome figure, with a long beard and a massive stature, living on a mountain in Wales. In the stories, Ysbaddaden is cursed and seeks a hero to fulfill a prophecy. He challenges Geraint, a brave knight, to complete various tasks to win the hand of his daughter, Olwen. Ultimately, Ysbaddaden's fate is tied to the hero's journey, showcasing themes of bravery and destiny.