Hagath's species was an undistinguished humanoid species from the Alpha or Beta Quadrant.
Two members of this species, Hagath and his subordinate Farrakk, were arms dealers that had made a presence in the Alpha Quadrant by the late 24th century. Regarding Hagath, Gaila once quipped to Quark that "If he were a bit shorter and his teeth were a little sharper, he'd make a perfect Ferengi." (DS9: "Business as Usual")