The Red Ribbon ScientistDr. Gero is the head scientist of the Red Ribbon Army (though he is never seen at the time) that created the first androids in the service of the Red Ribbon Army. In the anime, a Dr. Flappe (who looks nothing like Dr. Gero) is named as Android 8's creator. A possible explanation is that Dr. Flappe and Dr. Gero were partners and constructed the first androids together (most likely including Android 8 ) or that Dr. Flappe merely constructed Android 8 while Dr. Gero produced the blueprints and forced Dr. Flappe to create him (most likely the latter as Flappe was hinted at being a Red Ribbon member against his own will).
The Quest For VengeanceAfter the Red Ribbon Army was defeated by Goku, Gero went into hiding in a mountain area that was north of North City where his laboratory was located. In this lab, he strived to create the ultimate fighting machine. Using an extremely inttelligent tracking device disguised as a ladybug, he studied Goku and the Z Fighters for years on end: the fights Goku had with Tien Shinhan, Demon King Piccolo, Piccolo, and the Saiyans Raditz, Nappa and Vegeta.
Dr. Gero ceased the study of Goku's power when the Saiyan left for Planet Namek, believing he had already compiled enough information, so he simply adjusted the androids' power levels to accommodate for Goku's expected power increase, not accounting for the power level of Goku's Super Saiyan form. Believing he had created the ultimate fighting machines, he finalized his plans and constructed a series of Androids.
The Androids Are UnleashedA year after Namek's destruction, Future Trunks informs the Z Fighters that two extremely powerful Androids created by Gero will appear shortly. Three years later, on May 12th at 10:00 am, on an island nine miles south-west of South City, two Androids appear: Android 19 and Android 20. Together, they kill many people, including a man who has his head ripped off by Android 20. Yamcha is the first to find them, as they were attracted to his Power Level.
Before Yamcha could act, Android 20 demonstrates a deadly power, Dr. Gero's latest design for Androids included an energy absorbing function. Using a small red jewel embedded in his hand, he grabs Yamcha by the jaw, punches a hole through his body, and saps his life-force. After an explanation of their origins to Goku, Tien Shinhan and Piccolo, Android 20 single-handedly destroys half of the city with his Bionic Punisher technique. Goku leads him and Android 19 out of the city, to avoid killing more people in the fight. In some unknown island, Android 20 begins to explain to Goku why Gero wants to have his revenge on him for destroying the Red Ribbon Army. After the explanation, he orders Android 19 fight Goku. Due to the Saiyan's Heart Virus that manifests at that exact moment, Android 19 wins. After Vegeta turns into a Super Saiyan and destroys Android 19, Android 20 runs away.During the ensuing search, Android 20 attacks Piccolo from behind, only to be foiled by Gohan. He tries to fight Piccolo head-on, but Piccolo is superior by far as a result of three years of intense training with Goku (and probably also the fusion with Nail). Piccolo mercilessly severs the android's arm and prepares to destroy him when he (the Android) retreats once again into the rocky mountains. Android 20 decides to retreat into his lab, in order to activate Android 17 and Android 18. Having recognized him as Dr. Gero, Bulma notifies the Z Warriors about the approximate area of his laboratory and they depart for the north.
While approaching his lab, Android 20 ambushes Krillin but spares him in his hurry to activate his Androids. Krillin follows him to his lab and summons the Z Warriors there. Android 20 enters his lab and activates Android 17 and Android 18, having a controller that can deactivate in case they rebel again. The androids fool him into believing they are obedient, until they snatch the control from him. After crushing it, they brutally murder him by severing his head. His remains are later destroyed along with what seems to be the rest of his laboratory at the hands of Future Trunks when he fires a blast with the intention of destroying Android 17 and Android 18.
Cell's RememberenceDuring Imperfect Cell's flashback to Piccolo, it is explained how Dr. Gero (in his human form) had discovered a way to fuse together the cells from the strongest warriors to walk Earth (Goku, Piccolo, Vegeta, Frieza, and King Cold) and create a supreme fighting entity. After realizing that his project would take too long to be completed before his time, he decided to turn attention to other matters and leave his supercomputer from the lab to complete Cell. During Super Perfect Cell's flashback, Gero (in his Android 20 form) is shown killed by Future Android 17 and Future Android 18 he is killed as he finishes off the settings for the supercomputer to begin working on completing Cell (which contradicts his previous statement that Dr. Gero abandoned it).
HellBy means unknown, Dr. Gero has been permitted by King Yemma to keep his android body while entering Hell. Along with Super Perfect Cell, Frieza, King Cold and the Ginyu Force, Dr. Gero watches the final battle between Goku and Kid Buu, being one of the very few people cheering for Kid Buu.
Escape from HellDr. Gero is first seen in Dragon Ball GT in hell along with Dr. Myuu. There, they worked on a plan to create the ultimate android which could destroy Goku. They came up with a plan to combine both of their technologies and get a perfect Android by fusing Android 17 and Hell Fighter 17 to create Super 17. They then created a dimensional hole to get both androids in the same place - Earth. During the fight with the Saiyans, he is betrayed by Dr. Myuu who commanded Super 17 to kill him, leading to his somewhat ironic death (killed by Android 17 again). Dr. Gero was later sent back to Hell.
The exact strength of Gero in his Android 20 form is never elaborated on, given his short time menacing the Z Fighters. However, if 19's struggles against Super Saiyan Vegeta are any indication, both he and Android 20 are nowhere near the power of a Super Saiyan in spite of their confidence when witnessing Goku transform. Android 20 also briefly faces off against Piccolo and appears to be completely outmatched, with Piccolo's power even lower than that of a Super Saiyan.
Considering Android 20 was able to take down Yamcha (who had previously been seen defeating Recoome), it is probable his power is somewhere above the Ginyu Force's and probably around Frieza's final form.
Aside from his incredible intelligence (one of the best in the world, impressing even Capsule Corporation president Dr. Brief), Dr. Gero has gained combat abilities due to placing his own brain into an energy-absorbing model android.
- Built in Scouter – Built into his own Android body is a scouter that allows 20 to detect energy levels.
- Levitate – Like most characters in the series, Gero can fly in the air. However, like most Androids, he does not possess ki, so he flies by the means of a certain machine called Hikou in his body.
- Energy Absorption – As Android 20, Gero has special pads on his palms that allows him to absorb life-energy from his victims by grabbing them.
- Energy Attack – The most basic form of energy wave used by androids.
- Photon Wave – A Full Power Energy Wave. From his energy-absorbing pads, 20 releases a massive wave of explosive energy that can level an entire valley.
- Pesky Fly – A rush attack Android 20 used against Krillin.
- Bionic Punisher – A powerful beam shot from both his eyes, which is strong enough to devastate an entire city, or pierce through someone.
- Finish Sign – A power up move that Dr. Gero used in Dragon Ball: Raging Blast.
- False Courage – A power up move that Dr. Gero used in Dragon Ball: Raging Blast.
- In the present timeline, Android 17 impales Android 20 with his hand and kicks his head off, then crushes it like an insect.
- In Future Trunks' and Future Cell's timeline, Future Android 18 distracts Dr. Gero by knocking over some equipment, and 17 cuts his head off. As he warns them about Cell absorbing them, 18 blows up his head
- In the movie Dragon Ball Z: Super Android 13!, he is impaled by a secret attack behind him by 18 and android 17 cuts off his head.
- In Dragon Ball GT, Super 17 launches a Full Power Energy Wave that blasts Dr. Gero to pieces. This is when he dies for the second time in the present timeline.
- Japanese dub: Koji Yada
- Ocean Group dub: Brian Dobson
- Blue Water dub: Jonathan Love (DBGT)
- FUNimation dub: Kent Williams
- German dub: Gerhard Paul
- Italian dub: Oliviero Corbetta
- Portuguese dub: António Semedo
- Brazilian dub: Aldo César (DBZ), Luiz Carlos de Moraes (DBGT)
Video Game Appearances
- Dragon Ball Z: The Legacy of Goku II
- Dragon Ball Z: Supersonic Warriors
- Dragon Ball GT: Transformation
- Dragon Ball Z: Budokai 2
- Dragon Ball Z: Budokai 3
- Dragon Ball Z: Budokai Tenkaichi
- Dragon Ball Z: Budokai Tenkaichi 2
- Dragon Ball Z: Budokai Tenkaichi 3
- Dragon Ball Z: Infinite World
- Dragon Ball Z: Raging Blast
- Dragon Ball Z: Raging Blast 2
- Dragon Ball Z: Tenkaichi Tag Team
- According to "Laboratory Basement", one of Gero's ventures outside of cybernetics includes plans for a gas-powered toaster oven.
- In both Super Android 13 and the brief flashback from GT, the dialog in which 17 kills him is different than that of the DBZ anime.
- The only human part of him as an android is his brain, which was transplanted into him by Android 19.
- An interesting point is that Dr. Gero transferred his own brain into an energy-absorbing model Android, rather than an infinite-powered one, like 17 and 18, which would allow him far greater power reserves that surpass untrained Super Saiyans. This would make Dr. Gero weaker than 17 and 18. Why he chose to be an energy-absorber rather than an infinite-power Android is unknown (though 18 hints that it may have been because he thought that an energy-absorbing model android was easier to use as a host).
- In Trunks' "flashback" on Dr. Gero's creation of the androids, Andriod 17 by smashing his brain with his hand.
- In the FUNimation dub, the G in his name is pronounced like a soft J, and the "er" is pronounced as such. While in the Ocean dub, they start pronouncing it differently, with the G sounding like a hard J, and the "ero" sounding more like "arrow," while in the original Japanese and translations that follow this pronunciation, the G in his name is a normal G, as in "grip," making his name "Geh-roh," as in grapple.
- According to Android 18, Dr. Gero destroyed all the other androids up to 15 (with the exception of Android 8, who was assembled by Dr. Flappe in the anime, (though the manga states otherwise, leaving no doubt as to who its real creator was).
- Right after Dr. Gero activates Androids 17 and 18, he replies to Android 18's statement, "I see that you have chosen to become an android," by agreeing and saying that he had "eternal life like ." This implies that the process of turning a human into an android completely halts their aging, thus making the cyborg immune to at least natural death/illness.
- Despite being part of the Red Ribbon Army, which played a major role in Dragon Ball, Dr. Gero was never even mentioned until the Trunks Saga in Dragon Ball Z. Strangely, when Trunks explains the androids to Goku, he talks as though Goku confronted Gero and spared his life, telling him he should have never let Gero go. Goku seems to confirm this, despite there has never been a meeting between the two. This dialogue was altered in Dragon Ball Kai, with Goku instead expressing surprise that someone in the Red Ribbon Army managed to escape its destruction.
- Contrary to popular belief, the destruction of the Red Ribbon Army was not the primary reason why Dr. Gero desired to create androids and cyborgs, as he reveals in GT that he always dreamed of replacing the entire human race with artificial beings even before Goku had defeated the Red Ribbon Army. This is seemingly supported by Android 8 being around during the existence of the Red Ribbon Army.
- In one flashback sequence from the episode "Double Trouble for Goku", Master Roshi refers to Dr. Gero as the "current leader" of the Red Ribbon Army. This is technically true because, his later creations aside, he is the only actual member left.
- In Dragon Ball Z: Supersonic Warriors, Dr. Gero has a what if saga creating androids to try and destroy Goku. Everytime he tries, Goku and his friends defeat him and foil his plans forcing Gero to return to his lab, defeated.
- In Hell, Dr. Gero is seen without his hat when he watches Goku's fight against Kid Buu. Soon in Dragon Ball GT, Dr. Gero is seen with his hat back on.
- During the Android saga Piccolo cuts off his right hand, but during and after the scenes of when he releases Android 17 and 18 the same hand reappears and disappears several times
- In Dragon Ball Z Kai, the part where 17 kicks off Gero's head is removed, though the head is still visible.