Maurice Hedgehog

'''Maurice Hedgehog was the grandfather of Sonic the Hedgehog, and thus the father of either Jules and Charles Hedgehog or Bernadette Hedgehog. Upon his birth, Sonic was given Maurice's name as his middle name and his other grandfather's as his first name. However, he subsequently had his name legally changed to Sonic, bearing no ill will towards either of his grandfathers. (CSE)

Background Information

 * Sonic's middle name was revealed as Maurice shortly after StH #50; his first name wasn't given in canon, though former head writer Ken Penders apparently intended it to be "Olgilvie."
 * It is unknown whether Maurice was Sonic's paternal or maternal grandfather, though the fact that his name has been revealed is more information that exists on any of Sonic's other three grandparents.