Mobigypt

Mobigypt was an ancient civilization on Mobius, highly advanced for its time. Mobigypt was filled with pyramids and obelisks, and the Mobigyptians were famous for writing down everything in hieroglyphics.

History
Doctor Robotnik traveled back in time to Ancient Mobigypt while searching for the Chaos Emerald of Immortality, with which he could live forever. While there, he also sought to prevent Sonic's ancestor Masonic the Hedgehog (the fastest bricklayer in Mobigypt) from meeting his future bride Penelope(who ran the nearby Chili Dog stall), so that they could never have children and Sonic would never be born in the future. This plan was thwarted by Sonic and Tails.

Robotnik made himself Pharaoh of Mobigypt, and forced all of his subjects (including Sonic, Tails and Masonic) to build monuments in his honor. He sought out the Chaos Emerald of Immortality in the pyramid of his own ancestor, Robotnikhotep I. Robotnikhotep was kept immortal by the Emerald as a mummy, but was eternally opposed by a mummified blue hedgehog (possibly Masonic's grandfather, who had built the pyramid), who had his own blue Emerald. When Robotnikhotep could not defeat this mummified hedgehog, Robotnik took the Chaos Emerald for himself and turned on Sonic. However, with the mummified hedgehog's blue Emerald giving him a blue energy shield, Sonic was able to defeat Robotnik and take back the Chaos Emerald.

Masonic and Penelope were married, with the ceremony presided over by the former Pharaoh (a falcon). Before Sonic and Tails returned to their own time, Sonic remodeled the face of one of Robotnik's sphinx-like monuments, so that instead of Robotnik it resembled Sonic and Tails.

Trivia

 * Mobigypt is based on Ancient Egypt.
 * Mobigypt is a portmanteau of the words "Mobius" and "Egypt."