Gero was the chief scientist of the Red Ribbon Army and a founding member of the organization. He designed the weapons of the Red Ribbon and created the first androids in their service. The Dragon Ball Z Android saga saw the genius Dr. Gero, a remnant of the evil Red Ribbon Army, return to battle as an unstoppable cyborg.
Dragon Ball Z's penultimate threat was the brutal androids, which were designed with the sole purpose of killing Goku and the other Z Fighters. Creating them and sending them to this task was none other than Android 2.0, a.k.a. The Good Doctor. He became the last numbered android in the series to complete his revenge, turning the seemingly fragile old man into a much greater threat. This, of course, raises a lot of questions in terms of how Gero actually became an android, why he did it, and why he chose to become the type of android he was.
The show has answers for almost all of this, making what seems like a serendipitous decision suddenly much more reasonable. Gero was a member of the Red Ribbon Army, creating all his advanced and numbered androids. One of these humanoid robots, Frankenstein's Monster-style Android 8, would eventually befriend a young Goku. Goku and his allies eventually defeated the Red Ribbon Army, and the boy was instrumental in ending their quest for world domination. Apparently, Gero had always dreamed of using androids to replace the human race, using the resources of the Red Ribbon Army to do so. However, after his defeat at the hands of Goku, Gero went underground, hoping to continue studying the young Saiyan to build something that would eventually defeat him.
Building several completely new androids, numbered 16 to 19, these assassins were prepared to eradicate Goku and the Z Fighters. Android 16 was even based on Gero's deceased son, who died in battle. This quest for revenge would even cause Gero himself to get his hands dirty on the battlefield. As another of the first robotic constructions, Android 8 made its Dragon Ball debut as part of the Red Ribbon Army. Flappe (thanks in part to the fact that Gero hadn't been created by Toriyama yet), Android 8 looked a lot like the Frankenstein monster, but in an uncheesy way.
One of the first androids to threaten peace on planet Earth was Major Metallitron, who was part of the Red Ribbon Army in the original version of Dragon Ball. However, in Future Trunks' Alternate Timeline, the androids succeed in their plans to destroy the world and manage to kill all the main members of the Dragon Team (except Goku, who dies from a heart virus, and Gohan, who survives but dies 13 years later) until Trunks destroys them almost 20 years later. Cell, a truly terrifying artificial life form, absorbed energy from its victims through its tail and eventually did so with Androids 18 and 17 as well, allowing it to complete itself and become “perfect” after undergoing a tremendous transformation. However, even though Freezer would eventually overcome him in Resurrection F's absurd climax, Cooler achieved a season as an all-powerful android god who was infinitely superior to Frieza's boring cyborg reconstruction. And while it seems feasible that both she and 17 have identical power levels, series creator Akira Toriyama says a glitch in 17's programming weakened him while 18 has full access to her potential. While not incredibly strong, Android 14 shows that its appearance is not just for show since it is capable of facing off against Goku and Trunks' combined efforts - even without transforming into Super Saiyans - which are exceptional warriors.Android 18 eliminates Ribrianne from her transformation and she returns to being Brianne who traps Android 18 in an energy trap while her companions from Universe 2 send her love which allows her to transform back into Ribrianne but with an increase in size. Consumed by anger over his defeat at Goku's hands during his time with Red Ribbon Army, Gero dedicated his abilities to making androids with one purpose: taking revenge on Saiyans no matter how long it took or what cost it entailed.
If he had been allowed to live indefinitely as an android who knows what deity-defying creations he would have been able to invent as technology continued to advance. They managed to create a duplicate of Android 17 which they then merged with Earth's 17 resulting in an incredibly lanky yet incomparably powerful Android champion. A man-made creation capable of rivaling a Super Saiyan 2 is worrying enough on its own but when you consider that he knew most of his enemies better than they knew themselves it becomes even more concerning. Bioandroids such as Cell and Cell Juniors are classified as earthlings presumably because they were created on Earth despite their extraterrestrial cells. With its genetic improvements it has super strength speed agility reflexes ability to fly telepathy telekinesis generate energy from its own being produce energy explosions absorb energy explosions absorb energy create force fields. Gero together with Android 17 returned to his laboratory after his unsuccessful attempt at defeating Goku's allies.