Very little is known about the criminal known as the Tinkerer. First encountered by Spider-Man early in the webspinner's career, he appeared to be the leader of an alien task force attempting to control the world. Though Spider-Man stopped the "invasion", the Tinkerer got away leaving behind only a rubber mask, leaving a confused Spider-Man to ponder just who or what the Tinkerer really was.
Years later, Spider-Man learns that the Tinkerer is an ordinary man who has an extraordinary talent for anything mechanical, and his "aliens" were really movie stuntmen in costumes, doing his dirty work.
Most recently, Tinkerer was severely injured by Punisher amidst the superhero Civil War. He recovered and went back to his work, but was eventually arrested. His son, Rick Mason struck a bargain with Norman Osborn to have the Tinkerer released upon completion of a single mission. Osborn agreed and kept his word after Mason delivered on his end.