Gwadyn Osol
An Arthurian warrior and a seldom mentioned member of the party formed to help Culhwch in his quest to locate Olwen.
Each member was chosen for a particular skill, that of Gwadyn Ossol being so heavy that under his feet even the highest mountain in the world would become a plain.
Notes
Gwadyn means sole.
Source
Culhwch and Olwen | Late 11th century