Menw fab Teirgwaedd, Menw fab Teirwaedd
Menw throws a spear at Ysbaddaden which is poisoned, and he shape-shifts into a bird during the epic hunt of Twrch Trwyth. As a bird he flew at the boar, trying to seize the razor, shears, or comb between its ears. He missed and was struck by the boar, wounding him. The wound left him weak for the rest of his life.
Each member of the party was chosen for his particular skills, and Menw fab Teirgwaedd was chosen for his mastery of magic, which would preserve the party in foreign and heathen lands because he could render them invisible.
Menw shows up several times in the Triads as a shapeshifter and an enchanter. The Triad no. 28 says he learnt one of the three “Great Enchantments” of Britain – the skill of shapeshifting from no other than Uthyr Pendragon. Another Welsh source calls him one of Arthur’s three Enchanter Knights, who had the ability to shape-shift. Some have seen him as a prototype for Merlin.
Culhwch and Olwen | Late 11th century
Triads of the Island of Britain (Welsh ”Triads”) | 11th century to 14th century
Breudwyt Rhonabwy | 13th century