Robotnikhotep had the Chaos Emerald of Immortality. The Emerald seemed to be cursed so that an ancestor of Sonic, a Mummified Hedgehog, protected the world from the wearer. He appeared to have a Blue Emerald that countered the Chaos Emerald's ability.
Despite possessing the Emerald of Immortality, Robotnikhotep was mummified and interred in a pyramid, where he slept within a sarcophagus in center of the burial chamber. When awakened, Robotnikhotep willingly gave the Chaos Emerald of Immortality to his descendant, Dr. Robotnik because he no longer wanted to live forever with the pesky Mummified Hedgehog. After giving Robotnik the Emerald, Robotnikhotep disintegrated into dust.
Dr. Robotnik later returned at an earlier point in time for the emerald. At that time, Robotnikhotep was in his coffin in one piece and wearing the Chaos Emerald of Immortality. Dr. Robotnik stole the emerald from him and Robotnikhotep became angry. Sonic and Tails arrived to find Robotnikhotep enraged, but Sonic did a Triple Spin which made his bandages unravel into nothing.
- The Egyptian word "hotep" was commonly used in the names of Ancient Egyptian figures.
- This character possibly got his name from Imhotep, an Egyptian Polymath.