A humanoid species born as twins who together make up a single individual, and whose loss of a twin can drive the survivor to vengeance.
The Miradorn are humanoids who are born as pairs of twins, each pair considered two halves of a single being.
In Vortex, a Miradorn named Ro-Kel was killed during a robbery in Quark's bar on Deep Space 9 by Croden, a fugitive from the Gamma Quadrant. His twin, Ah-Kel, sought revenge and attacked the runabout in which Odo was transporting Croden to his homeworld. Odo destroyed the Miradorn ship.