Some say he was expelled from his last adventuring party after they found out he had been clipping the other adventurers’s toenails while they were sleeping.

Some say he was a Noble’s Court Wizard, until he was sentenced to death for casting upon his Lord a spell to “shit his pants”

All we know is he’s called the Stig.

Let the other players make up the false rumors.

Neat idea.

Kind of similar to Fate’s standard game creation, where you go around and come up with how your backstory connects to everyone else. These connections can be invoked for bonuses later.