All of you ungrateful humans, who took everything away from me, will feel my loss and despair!
~ Professor Gerald Robotnik
The countdown marking my final revenge on this world has begun! In a few minutes, you will be destroyed! Soon, Space Colony ARK will hurtle through the atmosphere and crash into this world with cataclysmic force!
~ Professor Gerald Robotnik in Sonic X.

Professor Gerald Robotnik (simply known as Gerald Robotnik) is a brilliant but tragic scientist who is the late grandfather of both the late Maria Robotnik and Doctor Eggman, who also serves as the Bigger Bad in the videogame Sonic Adventure 2. He also appears as the posthumous antagonist of the Shadow Saga in the TV show Sonic X, which is loosely based on Sonic Adventure 2's story.


50 years ago, Gerald Robotnik was respected researcher, considered by many to be one of the greatest scientific minds in the world. At the presonal request of the president, he was offered a position onboard the Space Colony ARK by the United Federation, who wished to create "The Ultimate Lifeform", a being that could live forever. The military hoped to use the discovery of an "immortality formula" for weapons research, but Gerald refused the offer, believing that they were crossing the moral boundaries of nature. However, upon discovering that his beloved grandaughter, Maria Robotnik, was terminally ill, he changed his mind and accepted the position, in the hopes that he could use the research to discover a cure for her disease.

Many researchers did not believe the creation of an Ultimate Lifeform. to be possible, and began to name to project 'Project Shadow' due to it's apparently unreachable goal, as well as the level of secrecy the project required. Gerald liked the name, and it stuck.

Professor Robotnik initially experimented on the Chaos Emeralds and researched the results of applying chaos energy to living beings. The experiments proved successful and resulted in the creation of the Chaos Drives, which were used by the military as a power source for their robots.

Progressing on the next stage of Project Shadow, Gerald began experimenting on lizards, due to their ability to regenerate limbs; the result was the prototype Biolizard. Initially showing all desired traits as it matured, the prototype required a life support system fueld by Chaos Drives in order to survive, and it lacked to strength to even walk, despite the strength in it's tail and neck. Possessing the mind of a primitive animal, the Biolizard became more unruly and difficult to control as it continued grow.

Some time later, Professor Robotnik came in contact with the extraterrestrial Black Doom, and, using his DNA, created a more advanced being; Shadow the Hedgehog. Upon learning that Black Doom and the Black Arms race wished to harvest the human race as food, Professor Robotnik secretly developed the Eclipse Cannon in order to destroy them the next time they visited Earth.

However, the government soon concluded that Gerald's experiments were dangerous to humanity, and sent GUN to the ARK to neutralize them. Gerald managed to escape, but was immediately captured by the government and sent to Prison Island, where he was forced to continue his experiments. The government used him as a scapegoat, publicly declaring that the Ark had been shut down due to a devastating lab accident he had caused. GUN later managed to capture Shadow and sent him to Gerald, who discovered that Maria was among the casualties of the raid, and was stricken with grief over how his own research claimed the life his beloved granddaughter. Losing his will to live, he was driven insane, and became obsessed with exacting revenge on humanity. He made plans to send the ARK colliding with the Earth and destroy the planet once the 7 Chaos Emeralds were collected, programming Shadow and the Biolizard to ensure his plan's success. Unfortunately for Professor Robotnik, the government feared that Gerald would soon retaliate and had him executed, but not before the mad scientist left one final recording of his execution, in which he explained his plans for revenge.

Sonic X

Prof. Gerald Robotnik also makes an appearance as the true antagonist in the Shadow Saga in the animated TV series Sonic X. His story is very similar towards the story in Sonic Adventure 2, but with some differences. Some differences include; being unclear if Gerald Robotnik came in contact with Black Doom to create Shadow the Hedgehog.



  • In the photograph of him and Maria on Sonic Adventure 2, he was skinnier than his grandson. However, in the photograph of him and Maria on Shadow the Hedgehog, he is shown to be much bigger.
    • Also, his glasses on the photograph in Sonic Adventure 2 are smaller, but on Shadow the Hedgehog, they are bigger and take up nearly twice the space.
  • There seems to be a continuity error involving Gerald. G.U.N. raided the ARK to either kill or imprison everyone onboard. They somehow captured Shadow on Earth, but on the day of the raid, Gerald is imprisoned and stripped of all use of money and technology. This makes it impossible for him to record his motives on his diary, reprogram the ARK to fall to Earth, reprogram Shadow's brain to think he has to destroy the world, or produce a 50-year-old video of his own execution.
    • It could be that he hid from G.U.N. and lives through the raid and updated his diary and reprogrammed the ARK when the troopers left, then got captured again.
    • He could have been reprogramming the ARK while G.U.N. was attacking.
    • Or he had escaped imprisonment and got to the ARK, but arrested again and executed when he was done.