5 Worst Things Khan Noonien Singh Ever Did On Star Trek, Ranked

Of all the villains in the Star Trek universe, few, if any, are more genuinely menacing than Khan Noonien Singh, the genetically augmented superhuman and former dictator who awakens from cryosleep aiming to pick up where he left off during the Eugenics Wars. Played by Ricardo Montalbán in the original timeline and Benedict Cumberbatch in the Kelvin timeline, Khan is cold, calculating, ruthless, and guilty of many crimes.

Shortly after he is awakened from his 200-or-so-year suspended animation nap aboard the prison transport ship SS Botany Bay in the 1967 original series episode "Space Seed," Khan wastes no time manipulating ship historian Marla McGivers (Madlyn Rhue) into helping him pick up right where he left off, this time with designs on taking over the universe. When his efforts to rain mayhem down on the Enterprise fail, Captain Kirk (William Shatner) banishes the both of them along with the rest of Khan's foot soldiers to the Ceti Alpha system. Decades later, they meet again, this time with Khan bent on revenge against the cruel conditions his people endured after they were marooned. 

In all that time, Khan only gets worse with each new encounter. Whether he's rocking a Vidal Sassoon blowout or 1980s Grandma Bangs, the man is a full-blown menace in every timeline. Hang onto your ears as we rank Khan Noonien Singh's most villainous moves, from pretty darned bad to deeply trauma-inducing. 

Ruling as a tyrannical leader isn't a good look in any century. But, as Kirk is quick to point out in his Captain's briefing, Khan was a man of his time and "the best of the tyrants." 

As shown in the "Star Trek: Strange New Worlds" episode "Tomorrow and Tomorrow and Tomorrow" and the "Star Trek: Picard" episode "Farewell," Khan is first created with a handful of other children as a product of genetic engineering by shady scientist Adam Soong (Brent Spiner). After they grow up and seize power in more than 40 nations, their aggression and arrogance soon leads to them battling amongst themselves, an event that goes down in history as the Eugenics Wars. At one point, Khan rules over a fourth of the planet, from the Middle East to Asia, and ultimately becomes the last of the tyrants to be taken out of power. 

Although Khan was "the best" of the despots, he was still ruthless. Scotty (James Doohan) and McCoy (DeForest Kelley) note that there were no massacres under Khan's rule and he chose not to engage in warfare until attacked. However, Spock (Leonard Nimoy) is quick to point out that there was also very little freedom under Khan's rule as well. And by the end of "Space Seed," we've got a pretty solid idea of what that rule might have looked like.

Kirk's handling of the Khan situation in "Space Seed" is a bit baffling. It isn't long after finding the former warlord that Kirk and his people realize exactly who he once was, quickly deducing that these folks have most likely been stuck in stasis aboard a subluminal prison transport ship for a reason. So when Khan awakens in sick bay and holds a scalpel to McCoy's neck, does Kirk immediately ship him off to the brig or confine him to quarters? Nope, he gives Khan access to the ship's library before wining and dining him at the Captain's table in full dress attire. And it takes less than a day for Khan to start cooking up a little mutiny. 

Impressed by Khan's physique, power, and brutish sexism, Marla agrees to do anything Khan asks, which means beaming over to the Botany Bay to wake up Khan's other augmented buddies. And before you know it, they're attempting to take over the ship. A far cry from the supposedly benevolent ruler he once claimed to be, Khan is more than happy to let Kirk's crewmen watch their shipmates die one by one to get what he wants.

15 years after getting marooned on Ceti Alpha V in "Space Seed," Khan resurfaces in "Star Trek II: The Wrath of Khan," having taken control of the USS Reliant. In the days after their banishment, we learn Khan and his people faced immeasurable hardship. According to Khan, Ceti Alpha VI exploded a mere six months after their abandonment, turning  the neighboring Ceti Alpha V into a "barren sand heap" with only one native lifeform. Struggling to survive with only the contents of their cargo bay and Khan's ingenuity, the enhanced humans watched 20 of their people killed by Ceti Alpha V's eels. 

Not realizing they would encounter Khan there, the Reliant crew stops by Ceti Alpha V while working on the Genesis terraforming project. Khan doesn't need to read the fine print to know he wants to get his grubby little mitts on Genesis posthaste, immediately realizing its potential to take revenge against Kirk for abandoning his people and then failing to check up on them for a decade and a half. While there's certainly an argument to be made that Starfleet seriously dropped the ball with Khan and his people, most of whom never got their own individual trials, Khan's plans to use the Genesis project would be tantamount to genocide when used as a weapon of mass destruction.

Plans for world domination and genocide aside, nothing Khan does is as profoundly disturbing as the sheer body horror he injects into "The Wrath of Khan" using the local animal population on Ceti Alpha V. After explaining to Pavel Chekov (Walter Koenig) and Reliant captain Clark Terrell (Paul Winfield) that the not-so-friendly neighborhood eels killed his wife and nearly two dozen others, Khan goes into a little more detail on how the whole thing works before giving a personal demonstration. 

Describing the Ceti eels as not-quite-domesticated "pets," Khan explains to the captive Terrell and Chekov how "their young enter through the ears ... and wrap themselves around the cerebral cortex. This has the effect of rendering the victim extremely susceptible to suggestion." As the creatures grow while embedded in their victims' brains, Khan continues, they cause madness and eventual death in their hosts. 

Pulling out a couple of eel larvae, Khan then places one on both of the captives, who scream horrifically as the worms burrow into their eardrums and brains, transforming them into mind-controlled zombies. It's easily the most disturbing moment in the Star Trek canon, and definitely unforgivable. 

Khan's plans to engage in a mutinous murder fest or use Genesis as a WMD are no doubt terrible. But to Trek fans, there's truly little worse than killing off a beloved character and breaking up one of Trek's most iconic bromances at the same time. But that's exactly what happens when Khan's actions lead to Spock's death in "Star Trek II: The Wrath of Khan." 

Although he manages to get his hands on the Genesis device, Khan realizes it's all over for him after the Reliant is defeated in a space battle with Enterprise. He knows he's out of moves with Uhura's fateful command, "Surrender and prepare to be boarded." Whatever he thought he might have had planned for Genesis, Khan decides to just go ahead and detonate the thing, hoping to take out Kirk and the Enterprise, along with himself, in one final, desperate act of defiance during the ending of "The Wrath of Khan." 

For the Enterprise to survive and escape, some poor soul has to enter the radioactive warp core chamber. Because the "needs of the many outweigh the needs of the few," Spock logically chooses to fix the engine and sacrifice himself for the good of the crew. In one of Star Trek's most devastating moments, he and Kirk say their dramatic goodbyes from opposite sides of the warp chamber glass. Even if Khan couldn't have possibly planned it this way, causing Spock's horrific radiation poisoning death right in front of his bestie is as low as it gets.