Thoraxia

Thoraxia was a planet in the same galaxy as Mobius, though located many thousands of lightyears away. It was home to two insect-like races, the Blodex and the Bzzzz. During his time in space, Sonic the Hedgehog arrived on this planet. Using the planet's red Chaos Emeralds in an effort to transform into Super Sonic to defend the Blodex from the Bzzzz, the red Chaos Emeralds instead produced a duplicate being of Super Sonic, which began to rampage across the planet. Sonic managed to distract the duplicate long enough until it vanished. (StH: #126)

Months later, all of the red Chaos Emeralds were pulled away from Thoraxia and brought to Mobius by A.D.A.M.. (StH: #169)