Twrch Trwyth—the boar Trwyth—a mysterious being who can only be hunted by the whelp Drudwyn (a name meaning starling), who can only be held by the leash of Cwrs Cant Ewin, and the collar of Canastyr Caullaw (a name meaning hundred joints, hundred hands), and the chain of Kilydd Canastyr to fasten the collar to the leash... (Transactions of the Lancashire and Cheshire Antiquarian Society, v.24, 1907)

... Then they hastened towards the smoke, and they came so near to it, that they could see Dillus Varvawc scorching a wild boar.  "Behold, yonder is the greatest robber that ever fled from Arthur," said Bedwyr unto Kai.  "Dost thou know him?"  "I do know him," answered Kai, "he is Dillus Varvawc, and no leash in the world will be able to hold Drudwyn, the cub of Greid the son of Eri, save a leash made from the beard of him thou seest yonder.  And even that will be useless, unless the beard be plucked alive with wooden tweezers; for if dead, it will be brittle." (Mabinogion, Guest, 1910).