Pavel Chekov (mirror)

From Memory Alpha, the free Star Trek reference.

Ensign Pavel Chekov served aboard the Terran starship ISS Enterprise, under Captain James T. Kirk. Chekov existed in the mirror universe, and was the counterpart of Pavel Chekov. After a failed attempt to kill Kirk, he was punished with a trip to the agony booth. (TOS: "Mirror, Mirror")

[edit] Background

A continuity error occurs in "Mirror, Mirror" where the mirror Chekov boards the bridge turbolift with Kirk and Chekov is dressed as an officer. Inside the turbolift, Chekov is suddenly wearing an enlisted uniform, and then is back to officer status when the turbolift reaches deck five. While simply a production error, the events portrayed in TNG: "Parallels" have led some fans to speculate that Kirk might have shifted between another mirror universe (where Chekov was enlisted), and then back to the "regular" mirror universe due to a quantum flux effect caused by the transporter accident.

Like his counterpart, Chekov was played by Walter Koenig. Although no further references were made to the mirror Chekov, he plays a major role in the non-canon video game, Star Trek: Shattered Universe.