The Salmon of Knowledge is a creature in the Fenian Cycle of Irish mythology, sometimes identified with Fintan mac Bóchra, who was known as "The Wise" and was once transformed into a salmon.
Salmon of Knowledge
Scales on the Big Fish or Salmon of Knowledge sculpture, which celebrates the return of fish to the River Lagan
Close-up view of scales on The Big Fish or Salmon of Knowledge sculpture in Belfast
Fionn mac Cumhaill, often anglicized Finn McCool or MacCool, is a hero in Irish mythology, as well as in later Scottish and Manx folklore. He is the leader of the Fianna bands of young roving hunter-warriors, as well as being a seer and poet. He is said to have a magic thumb that bestows him with great wisdom. He is often depicted hunting with his hounds Bran and Sceólang, and fighting with his spear and sword. The tales of Fionn and his fiann form the Fianna Cycle or Fenian Cycle, much of it narrated by Fionn's son, the poet Oisín.
Fionn fighting Aillen, illustration by Beatrice Elvery in Violet Russell's Heroes of the Dawn (1914)
Fionn by Beatrice Elvery
"Malvine, Dying in the Arms of Fingal", by Ary Scheffer. The characters are from James Macpherson's epic poem Ossian: "Fingal" is a character based upon Fionn mac Cumhaill, while "Malvina" is the lover of Fingal's grandson Oscar, and cares for Fingal in his old age after Oscar dies.