A blob that eventually grows to be Llew Llaw Gyffes and Dylan the son of the wave spring forth when his niece Arionrhod steps over his wand, and he fashions a wife named Bloedeuwedd for Llew Llaw Gyffes out of flowers.  
The magic wand of this man's father is celebrated in Taliesin's Kerdd Daronwy.  A blob that eventually grows to be Llew Llaw Gyffes and Dylan the son of the wave spring forth when his niece Arionrhod steps over his wand, and he fashions a wife named Bloedeuwedd for Llew Llaw Gyffes out of flowers.  After he is tricked into going to war over a set of pigs, his nephew rapes his lover Goewin, for which this man turns him into a stag, then a hound, then a swine.  Dwelling at Caer Dathyl in Arvon, this man's feet must be in the lap of a virgin whenever he is not at war.  Lord over the land of Gwynned, this is - FTP - what sorcerer from Celtic myth, who along with his nephew Gwydion is thought to be the origin of the legend of Merlin.
The magic wand of this man's father is celebrated in Taliesin's Kerdd Daronwy.  
Math ap Mathonwy