Female Changeling
From FEInfobase
The Female Changeling had never been given a name and was leader of the Dominion during the Dominion War in the Alpha and Beta Quadrants. She formally surrendered to the Federation Alliance in late 2375 and agreed to stand trial for her war crimes against the Federation, the Klingon Empire and Romulan Star Empire.
The Female Changeling was believed to be the last of her kind by 2388 after it was reported that the Founder's Homeworld had been destroyed by the Borg. She was freed from Starfleet custody in agreement with Odo that she would not turn against the Federation Alliance ever again.