Odo in the Mirror Universe
In the DS9 episode "Crossover", Dr. Julian Bashir and Major Kira Nerys somehow end up in a parallel universe after traversing the Bajoran Wormhole. They arrive at Terok Nor, an alternate version of their Deep Space 9, where they meet several counterparts of people from their own universe, including Odo.
The mirror Odo serves as Terok Nor's security chief, but the main difference between him and Odo Prime is that he takes a sadistic pleasure out of his job. Rather than serving as a mere policeman on the station's promenade, he is a ruthless slave driver who works Terrans to death in the station's ore processing plants.During the episode, a thorium leak occurred in the ore plant and the workers were evacuated. In the confusion, Dr. Bashir snatched a phaser from one of the guards, setting it to kill and firing on Odo. Odo exploded in a shower of congealed goo.