Govannon
Son of Dôn and brother of Amathaon.
As one of his tasks, the hero Culhwch had to get Gofannon to deliver irons to the headlands of the giant Ysbaddaden. The character is adopted from Irish legend, where he is Gobniu, the god of the forge.
The divine smith whose honour it was, according to ancient Welsh law, to have the first drink or toast at any feast held in a chieftain’s court. Gofannon was said to have struck the blow that killed Dylan eil Ton.
Gofannon may have his origins in the Welsh father Gwydion and is undoubtedly the Welsh version of the Irish Goibhniu.
Source
Culhwch and Olwen | Late 11th century