Gorgol the Butcher was an orc of the First Age, slain by Beren. He is only mentioned once in The Lay of Leithian, during the recounting of Beren's deeds of valor as an outlaw in Dorthonion.
J.R.R. Tolkien, Christopher Tolkien (ed.), The Lays of Beleriand, "IV. The Lay of Leithian Recommenced", pp. 343-4