Gerald Robotnik

 Professor Gerald Robotnik (プロフェッサー・ジェラルド・ロボトニック Purofessā Jerarudo Robotonikku) is a character in the anime series Sonic X. He is the grandfather of Dr. Eggman's and Maria Robotnik. He is a world-renowned scientist who experiments with unique discoveries mainly at Space Colony ARK.

History
Many years ago, Gerald created Space Colony ARK, trying to develop the Ultimate Life Form. After the Biolizard, he finally created the Ultimate Life Form, Shadow the Hedgehog. It is unknown if he created Shadow with Black Doom or not. However, Maria died trying to protect Shadow from GUN (although in the dub, they took her away.), because the military feared Gerald would use it to take over the world. Gerald was then imprisoned at Prison Island, taking on a new purpose: get revenge. He was able to compel Shadow into getting revenge on Earth. He was found out and executed, but not before creating a video revealing his plan when all seven Chaos Emeralds were put into the Eclipse Cannon.

Space Colony ARK
Space Colony ARK was the creation a lab of Robotnik before GUN came and killed Maria. It was then sealed off.

The Eclipse Cannon
The Eclipse Cannon is a weapon on Space Colony ARK with enough firepower to destroy an entire planet. It needed the seven Chaos Emeralds to power it, although it was demonstrated that with six Chaos Emeralds, it can destroy half of the Moon. It is unclear why Robotnik created it, though.

Bio Lizard
The Bio Lizard was one of Robotnik's prototypes of Project Shadow. It needed a life support system, so it was no use to Robotnik and he sealed it away at the core of the Eclipse Cannon.

Shadow the Hedgehog
Shadow is Robotnik's most successful creation, although it is unclear how he was created. Shadow could go as fast as Sonic, teleport using Chaos Control with just one Chaos Emerald and transform into Super Shadow.

Trivia

 * Gerald's diary entry and ultimately, his motivations, were different in comparison to the games. When he was escorted to the Union Army Prison, he wondered who could possibly believe that someone arrested him. He also implies in his rants in his diary that he was the creator of the "pseudo-perpetual mobile Chaos Drives." He also wonders if his arrest had anything to do with a conspiracy by GUN to take over the Eclipse Cannon and Artificial Chaos, and mentions that Project Shadow is the only thing in his mind, and that he won't stand for such immorality. The diary omits any references to Maria's death or the fact that her death drove him insane. It also contained two cases of swearing in the diary ("Oh, hell" when he discovers that he was going to be locked up in the Union Army Prison and "for christ's sake" when expressing his distaste at being locked up and citing his being the father of the pseudo-perpetual mobile Chaos Drives), a rarity at the time.