The poem Pa Gur in the Llyfr Du Caerfyrddin talks of the fight between Cei and Cath Palug, Palug’s cat. Bromwich states:
“Cath Baluc is probably to be associated with the murchata or monstrous sea-cats of Irish tradition.”
Murchata may have derived from the Irish name Murchadh which appears in the last line of Triad 15:
“Three Roving Fleets of the Island of Britain:
The Fleet of Llawr son of Eiryf
and the Fleet of Divwng son of Alan,
and the Fleet of Solor son of Murthach”
Note, Bromich writes:
“The spelling with –th– in place of –ch– in the triad and elsewhere would be a simple transposition.”
Bromwich suggests all three fleets belonged to Irish raiders. Cath Palug represents the leader of one of these marauding fleets. Muredach was the son of Eogan who was the son of Niall Noigiallach. As, Murthach would have been born about a century after Niall it is likely he would have been a contemporary of Cei and Arthur.
 Bromwich, R., 2006, 474.
 Ibid., 455.
 Ibid., 30.