The mirror-universe Garak is the Intendant's Cardassian second-in-command on Terok Nor, a brutal and ambitious officer who repeatedly schemes to take her place and never quite succeeds.
In the mirror universe Garak is no exiled tailor but a serving Cardassian officer and the Intendant's deputy aboard Terok Nor. He lacks the subtlety of his prime-universe counterpart, preferring threats and torture to wit.
In Crossover he plots to have the Intendant assassinated and to install the visiting prime-universe Kira in her place as a puppet, a plan that collapses when the visitors escape. In Through the Looking Glass (2371) he is still at the Intendant's side, enduring her contempt while hunting the Terran rebels.
He returns in Shattered Mirror, where he has fallen from favour after losing the station, and in The Emperor's New Cloak, in which his long run of narrow escapes finally ends.