Saltah'na

The Saltah'na were an ancient Gamma Quadrant species, which had driven themselves to extinction by the 24th century. In 2369 the IKS Toh'Kaht discovered the remains of the Saltah'na civilization, the same civil war which destroyed the Saltah'na spread to the Klingons and the ship only just managed to returned to the Alpha Quadrant before being destroyed. The Saltah'na influence then spread to Deep Space 9, amongst other effects causing Benjamin Sisko to obsessively construct a Saltah'na clock. The crew were eventually able to resist and break free of the Saltah'na influence. (DS9 episode: Dramatis Personae)