When you want a TV show about space aliens punching each other, all in the name of saving the universe, then look no further than Dragon Ball Z. Goku is the central protagonist in the Dragon Ball franchise, but many other characters are equally interesting. Part of what makes Dragon Ball and every follow-up show so engaging, aren’t just the heroes, but the villains. There are space pirates, evil genies, demons, and of course, homicidal androids; it might sound like overkill, but each villain is unique and interesting in their own way.

One group of antagonists that threatened the planet like never before were the villainous androids created by the insane Dr. Gero. Fueled by a healthy hatred for Goku, Gero turned himself into an android and created more mechanical monsters, to do his dastardly work of killing the Saiyan and conquering the planet. Despite Gero’s intentions, the androids, especially Android 17 and 18, would rebel against their programming and instead find delight in killing. Even the diabolical Cell, though inspired by Gero to rule, would later have his own delusions of grandeur. Today at CBR we’re looking at 15 dark facts about Dragon Ball Z’s androids you might not know.

15 GOKU NEVER DEFEATED AN ANDROID

At least in canon. Goku is the hero of the Dragon Ball franchise. He’s defeated nearly every villain he’s come across, except when it comes to the Androids. During the Android Saga, Goku is surprisingly absent, bed-ridden on account of a heart condition. Before that however, Goku fights Android 19 and loses rather badly. He’s unable to keep up with the android and is himself weakening on account of his heart condition.

Even after the androids are no longer the show’s central threat and the antagonist switches to Cell, Goku is once again unable to claim victory; Goku stalemates Cell. The only reason he fought the android was to give his son Gohan a chance to see how Cell fought and formulate a plan to defend himself against the monster. Goku also never has a chance to battle either 17 or 18 since Cell absorbed them.

14 THEY'RE BASED OFF THE TERMINATOR

"The Android Saga" is made up of two manga volumes, the second of which is titled Rise of the Machines. If that sounds familiar, then rest assured it isn’t a silly coincidence. Turns out, Akira Toriyama was inspired by The Terminator film series. When "The Android Sag" was experiencing its manga release, it was in 1992, the same year as Terminator 2: Judgment Day. "The Android Saga" and The Terminator series bare some striking similarities.

First, both the Terminator and the DBZ androids pop up on May 12. Trunks play the Kyle Reese role, as he’s sent from the future to warn of a robot apocalypse. The future leader of the resistance, Gohan is the John Connor of Dragon Ball. Terminator 2’s villain, the liquid T-1000 was a being of incredible regenerative powers, like Cell. Additionally, 16 became good, similar to Arnold Schwarzenegger’s Terminator.

13 DR. GERO FORCIBLY TURNED 17 AND 18 INTO ANDROIDS

If you only watch the anime, then there’s a lot of character history you miss. Dragon Ball lore is notorious for having an expanded history that only truly dedicated fans know about or take time to discover. Many people don’t know it, but Androids 17 and 18 didn’t sign up to get turned into cybernetic nightmares. Rather, Dr. Gero kidnapped them while they were teenagers.

At the time of their kidnapping, Gero considered them as a pair of “delinquents.” Gero stumbled across the twins completely by accident, while he was searching for subjects on whom to experiment. Deciding they were perfect for his needs, Gero abducted them. The twins almost never speak of their past. Not much is known about their upbringing except they were born to human parents, and 18 is the older of the two.

12 THEY'RE JUST FOOD FOR CELL

Everyone and everything has a purpose. Alas for some, their purpose is to be served up as food to a genocidal bio-android. There are different categories of androids. The first has an unlimited energy supply. Androids 16, 17, and 18 fell into this category, but their kind were the most difficult to control; hence them killing Gero. With unlimited energy, never growing fatigued in battle, the androids could fight for long periods of time and they could get stronger through training.

Unlike other androids, these models also have the advantage of being undetectable when trying to sense an opponent’s Ki. Though 17 and 18 relished in their power, Gero didn’t design them to be freethinking individuals. Rather, they were meant only to serve as food for Cell, his ultimate creation. Once he absorbed them and their abilities, Cell was supposed to become the ultimate being.

11 ARALE IS THE STRONGEST ANDROID

The Dragon Ball franchise is chock full of characters and Toriyama often forgets a lot of what he’s written, sometime its decades before someone or something reappears. To some fans Arale Norimaki may be unfamiliar, but she is both the first and strongest android to appear in all of Dragon Ball. Though she appeared in the original Dragon Ball, Arale is a gag character and the protagonist of manga series Dr. Slump, also created by Toriyama; she’s far stronger than anyone Goku’s fought.

During Dragon Ball she easily beat General Blue from the Red Ribbon Army. Impressed, Goku invited Arale to the next World Martial Arts Tournament. She didn’t attend, but she showed up decades later in Dragon Ball Super. She effortlessly outclasses Vegeta in a sparring match and takes on Super Saiyan Blue Goku. She later says she’d like to battle again but at one hundred times the power.

10 MAJIN BUU ATE ANDROID 18

The evil wizard Bibidi created Majin Buu. The pink, impish creature was a malevolent djinn and the most powerful villain in the entirety of Dragon Ball Z. Upon getting resurrected by Bibidi’s son Babidi, Buu went on a rampage, tearing through the Earth’s protectors. Buu’s power was unlike anything the Z-Fighters had ever faced before. Buu’s first order of business was to effectively kill Super Saiyan 2 Vegeta, Over the course of the series, Buu became gradually stronger and at one point becomes Super Buu.

In a desperate gamble, Piccolo traps Buu, along with himself and Goten and Trunks, in the Hyperbolic Time Chamber. Enraged, Super Buu created a rift in space and time and escapes. When he makes it back to the world, the remaining Z-Fighters, including Android 18, confront him. Casually, Super Buu turns them all into food and eats them with absolutely zero remorse.

9 17 AND 18 HAVE DIED MULTIPLE TIMES

Nearly every character on Dragon Ball Z has died at least once and there are even characters who have died multiple times. Due to the hijinks of time travel, 17 and 18 have died twice. The first time was after Trunks returned back to his timeline after helping the Z-Fighters vanquish Cell. Now stronger than ever, Trunks hunts down the evil Androids and easily kills them.

The other time they died involved the malevolent Majin Buu. At one point Super Buu turns Android 18 into a piece of chocolate and then eats her. As for 17, Buu would later destroy the Earth, along with all its inhabitants; it’s safe to assume 17 died. Later, in Dragon Ball GT, two Android 17s fuse into Super 17; Goku kills him.

8 THEY KILLED FUTURE GOHAN

Trunks, the half-Saiyan son of Vegeta and Bulma, comes from a world very much like the one Goku and friends live in, with one exception: practically everyone is dead. Androids 17 and 18 were infinitely more ruthless in Trunks’ timeline. Rather than toying with Earth’s heroes, as they do in the altered timeline Trunks changed when he tried to warn Goku and the others, these androids are bloodthirsty monsters. After driving humanity to the verge of extinction and wiping out most of Earth's’ heroes, only an adult Gohan and a young Trunks are left to defend the world.

Ultimately, both their efforts are futile. Much to the surprise of the audience and Trunks too, 17 and 18 kill Gohan in one dramatic standoff. Though he dies, Gohan’s death serves as the motivating factor Trunks needs to turn Super Saiyan. Years later, he’s able to finally avenge his fallen friend.

7 THEY'RE STRONGER THAN SUPER SAIYANS

Up until the Frieza Saga, and even beyond, the premise behind the Super Saiyan was that it was a legendary and unstoppable warrior. Goku seemed to prove the legend true when he defeated Frieza. Later, Trunks, after turning Super Saiyan, would also beat Frieza, and pretty easily at that. The notion that a Super Saiyan could experience a dramatic defeat didn’t enter in the minds of anyone. That was until the androids reared their ugly heads.

Though Vegeta easily bests Android 19 and sends Dr. Gero running for the hills, quite literally, once Gero unleashes Android 17 and 18, things take a turn for the worse. With little effort, 17 and 18 beat Super Saiyan Trunks and Super Saiyan Vegeta, the former of which was stronger than Goku. This display of strength proved their power was superior to early Super Saiyan levels.

6 ANDROID 16 IS MODELED AFTER GERO'S SON

Dr. Gero absolutely hated Goku. It was, after all, why he turned himself into a killer android and created other androids to raze the world. However, Gero’s path to evil actually began when Goku was just a kid, from when the young Saiyan destroyed his Red Ribbon Army androids. Yet his vendetta runs deeper than many realize. Turns out, Gero’s son was a high-ranking soldier in the Red Ribbon Army who was shot and killed by an enemy soldier. Though Goku didn’t participate in the death of Gero’s son, he was responsible for destroying the Red Ribbon androids, the weapons Gero’s son died fighting for.

Grief-stricken, Gero created Android 16, modeling the cyborg off his dead son, which explains why Gero didn’t want 16 to go into battle. 16 is released before his programming is complete and tried to destroy Cell, Gero’s “perfect” creation.

5 THEY'VE TERRORIZED MULTIPLE TIMELINES

The Androids are terrifying villains. Not only do they have power that makes them stronger than the average Super Saiyan, but their terror wasn’t limited to one timeline. Far from it, as in fact they have spread fear through multiple timelines. Similar to the more horrible Cell, the Androids exist in two different points in history.

The first time they popped up was in the History of Trunks timeline. Here, they killed all the Z-Fighters and nearly murdered every remaining human on the planet. The second time they would appear was in the timeline Trunks accidentally altered when he went back in time to warn Goku and the others about the impending android threat. Unfortunately, Trunks’ warnings is for naught as the mechanical monstrosities surface anyway, stronger than they were on his world, and proceed to spread chaos yet again.

4 TORIYAMA'S EDITOR DIDN'T LIKE THEM

The Android and Cell Saga are two of the most important series in the Dragon Ball franchise. With a truckload of iconic moments, it’s impossible not to visualize Dragon Ball without either the Androids or Cell. Originally, Cell was never going to be a part in the show. This was because Toriyama’s editor wanted a pair of androids to be the central antagonists. Toriyama suggested Android 19 and 20, but they didn’t quite fit the bill.

Per Kazuhiko Torishima’s request, Toriyama did away with 19 and 20 and replaced them with 17 and 18. This worked well, until Torishima decided he didn’t like 17 and 18 either. Toriyama then created Imperfect Cell, but first-form Cell is only “Imperfect” because Torishima didn’t like his design. Toriyama never meant for Cell to transform, but having Cell absorb the androids, allowed for he and Torishima eventually to choose Perfect Cell.

3 17 AND 18 HAVE FUSED TWICE

Dragon Ball Z video games are wild, absurd, and generally a whole lot of fun! One of the things the video games do, that fans of the franchise love, is offering many different stories and possibilities. Though official Dragon Ball canon is spoken for, video games have all the legroom they need to include “What if” scenarios. The 3DS Dragon Ball Fusions game matches the description perfectly. The game itself allowed for wild android fusions that can be made though the game’s fusion system.

To no one’s surprise Android 17 and 18 becoming a fused fighter was included and they go by the name Android 1718. Considering the properties of fusions, it’s generally assumed that they became remarkably powerful. In the arcade game Dragon Ball Heroes, Super 17 and Android 18 fuse together and easily beat Super Saiyan 4 Goku and Vegeta.

2 THEY PSYCHOLOGICALLY TRAUMATIZE THEIR VICTIMS

Androids 17 and 18, actually every single android Gero created, were all horrifying monsters. With the strength that exceeds that of a Super Saiyan, it’s difficult not to marvel and tremble at their raw might. Still, it’s rather the sadistic pleasure they get out of psychologically tormenting their victims that make them scary. With Cell, it’s plausible to believe he received his fondness for scaring the heck out of people from the genes he shared from Frieza and Demon King Piccolo. Android 17 and 18 don’t share genes with any other characters in Dragon Ball, but they still delight in tormenting all the unfortunate souls they meet.

Even before they got turned into androids, 17 and 18 were already delinquents. After the process was done to them, they became unstable and unhinged, their terrible personalities magnified all the more by the experiments they endured.

1 DR. GERO IS KRILLIN'S FATHER-IN-LAW

The Dragon Ball Z tree of genealogy isn’t especially overcomplicated. For our purposes, we’re looking at the Android family tree. In Dragon Ball Z, shortly after the Cell Saga, Krillin and Android 18 get married. Together the two have a daughter and are very much in love with one another, Krillin having fallen for 18 the moment he laid eyes on her. In the History of Trunks timeline, 18 and Krillin don’t share the connection, and she, along with her brother, murder the Z-Fighter.

Regardless, once Krillin and 18 do get married, that introduces some new family members to Krillin’s life. Since Android 17 and 18 are technically twins, Android 17 is Krillin's brother-in-law. The two haven’t interacted much, but 17 generally seems to approve of 18’s choice. The more awkward family member is Dr. Gero; he’s effectively Krillin’s father-in-law.