Failinis

Failinis [FAW IHN-ish] or Ṡalinnis/Shalinnis is a dog in the Mythological Cycle of Irish literature, belonging to Lugh Lámhfhada of the Tuatha Dé Danann; it was one of the eric (reparation) items exacted from the sons of Tuireann.

It was originally the a hound-whelp of the smith or the king of Iruaith (Ioruath, Hiruaidhe, etc.). Later on, Lugh's Failinis (var. Fer Mac) belonged to a foreign threesome from Iruaith that came to Ireland, and encountered by the Fíanna led by Fionn mac Cumhaill in the Fenian cycle.