|This character exists primarily within the Adventures of Sonic the Hedgehog continuity.|
Information in this article may not be canonical to the storyline of the games or any other Sonic continuity.
I've been waiiitiing... five thousand years for this!
— The mummified hedgehog, "Robotnik's Pyramid Scheme"
The Mummified Hedgehog wears a necklace with an emerald around his neck, which allows him to activate a blue shield that makes him immune to the powers of anyone wearing the Chaos Emerald of Immortality. He lets Sonic borrow the emerald so he can defeat Dr. Robotnik, who took the Chaos Emerald of Immortality from Robotnikhotep. After Robotnik was beaten, Sonic returned the emerald and the Mummified Hedgehog went back in his coffin.
The Mummified Hedgehog is the archenemy of Robotnikhotep. They seem to have a relationship very similar to that of Sonic and Dr. Robotnik.