Star Trek's original captain, James Tiberius Kirk, had many doppelgangers during his adventures. Memorably played by William Shatner, Kirk remains one of the most iconic Star Trek personalities and holds an enduring reputation for his trademark acting style. But while Shatner portrayed Kirk both on TV and film, he wasn't always playing Kirk in his Star Trek appearances, as the character was duplicated, possessed or otherwise copied a surprising amount of times for one of Starfleet's elite.

Using darker versions of established characters as villains was a cheap, but sometimes very effective method Star Trek used to keep within its modest 1960s budget, and while some of the following examples simply wouldn't work in any other era, others have lingered on to become a core part of Star Trek canon. Elsewhere, time travel and franchise reshuffling have given rise to a whole new version of Kirk on the big screen.

The life of a starship captain is already full of ups and downs, but facing otherworldly threats on a daily basis is hard enough without the commander of Starfleet’s flagship being taken over, replicated or impersonated by hostile forces, and creates a huge headache for the entire crew. These are the various times in James T. Kirk's career where he wasn't quite himself.

Evil Captain Kirk In "The Enemy Within"


Star Trek's debut season introduced two classic science fiction tropes: the transporter malfunction and the evil version of the show's main hero. Owing to an ill-timed transporter glitch, the dashing Captain Kirk is split into two distinct halves, one overtly good and one devilishly evil, and if nothing else, the episode gave William Shatner a chance to flex his unique acting chops. While 'good Kirk' was extremely placid, somewhat anxious and lacking his usual decisiveness, 'bad Kirk' saw Shatner hit full throttle, assisted by some wicked lighting to accentuate his unhinged facial expressions.

During bad Kirk’s tenure as Enterprise captain, he beats up a technician, drinks copious amounts of Saurian brandy and attempts to sexually assault his Yeoman, and it doesn’t take long for the crew to work out that there are two Kirks aboard that can’t exist without the other. Eventually, both Kirks step on the repaired transporter platform and are joined together once again.

Robot Captain Kirk In "What Are Little Girls Made Of?"


Another season 1 episode, "What Are Little Girls Made Of?" featured a stereotypical mad scientist who develops a method of creating humanoid replicas by using a wheel of fortune and a lump of clay. In a manner not entirely dissimilar to Jean-Luc Picard's recent resurrection, the lump of clay transforms into an exact duplicate of the naked person laying next to it, then that person's memories are installed into the copycat.

This is good news for Kirk who, while laying on the table, overhears this aspect of the process and repeats a phrase to himself, hoping it will be embedded into his replica’s memory. Kirk's chosen phrase acts as a signal to Spock, so that when the Vulcan asks an innocuous question to a calm Kirk, he receives an angry, curt response from the captain. This sudden outburst is enough for Spock to realize all is not well and he leads a security detail down to Exo III to save the day. Robot Kirk is disintegrated by a female android who the real Kirk had kissed earlier, confusing her circuits with pesky human emotion.

Mirror Captain Kirk In "Mirror, Mirror"


Moving into Star Trek's second season and one of the franchise's most memorable and influential episodes, "Mirror, Mirror" paved the way for a concept that would remain relevant through the decades - the alternate, evil Mirror Universe. Another transporter glitch coupled with an ion storm causes Kirk and his landing party to swap places with their counterparts from another universe, and these mirror crew members hail from a reality far more harsh and unforgiving than the one the Enterprise exists within.

The story focuses on the Prime Universe crew and their efforts to get back home, complicated by assassination attempts, paranoia and a very creepy Sulu. The evil characters aboard the Enterprise are only featured in one scene that sees them promptly confined to the brig amid lots of shouting and a furious, savage Kirk who clearly misses Spock’s beard and attempts to bribe his way free. As Spock later explains once Kirk and co. are safely back home, it was far easier for civilized people to impersonate barbarians than the other way round.

Possessed Captain Kirk In Return To Tomorrow


Rather than a Kirk impersonator, "Return To Tomorrow" sees Kirk taken over by a non-physical entity, but in a departure to the standard trope, the possession is purely voluntary. Kirk and his crew come across three ethereal, highly-evolved beings who are delicately housed in small spheres, unable to physically interact with their surroundings. Using members of the Enterprise crew as avatars, these non-corporeal life forms are able to build sophisticated robotic bodies which their consciousnesses can then inhabit, giving them a physical vessel. Kirk, Spock and Lt. Commander Ann Mulhall volunteer for the process, with Kirk’s body possessed by the group's leader, Sargon.