Mobium

The Mobium is the currency of Mobius. A 12 Mobium bill has Sonic's face on it.

The currency was used in Adventures of Sonic the Hedgehog, Sonic Underground and the Sonic the Hedgehog comic book series.

Trivia

 * In the pilot episode of Adventures of Sonic the Hedgehog, the currency symbol on Sonic's reward poster is a G-clef.
 * In Sonic Christmas Blast, Sonic (disguised as a binman) charged Scratch and Grounder 10,000 "Robotnik-bucks".