Sonic the Hedgehog (character)

Sonic the Hedgehog was, according to differing accounts, either the main character in the video game of the same name, (PROSE: Business Unusual, etc.) or a real individual who could run at high speeds. (WC: New Adventures Await!)

Biography
Sonic swiped a floating ring out of Gollum's grasp inside a dark cave. (WC: New Adventures Await!)

Other references
He was a blue hedgehog. (PROSE: Business Unusual)

Ace joked with Dr John Watson that whatever the Rakshassi were worshipping, it wasn't Sonic the Hedgehog. (PROSE: All-Consuming Fire)

Martha Jones once described the Tenth Doctor's hair as "very Sonic the Hedgehog", although the Doctor said he was going for more of a Sid Vicious vibe. (PROSE: Forever Autumn)

Information from invalid sources
Sonic had apparently heard of the Doctor before meeting him, and was impressed when he erroneously heard that he named the sonic screwdriver after him. (NOTVALID: LEGO Dimensions)